Functions
subroutine slagge (M, N, KL, KU, D, A, LDA, ISEED, WORK, INFO)
SLAGGE
subroutine slagsy (N, K, D, A, LDA, ISEED, WORK, INFO)
SLAGSY
subroutine slahilb (N, NRHS, A, LDA, X, LDX, B, LDB, WORK, INFO)
SLAHILB
subroutine slakf2 (M, N, A, LDA, B, D, E, Z, LDZ)
SLAKF2
real function slaran (ISEED)
SLARAN
subroutine slarge (N, A, LDA, ISEED, WORK, INFO)
SLARGE
real function slarnd (IDIST, ISEED)
SLARND
subroutine slaror (SIDE, INIT, M, N, A, LDA, ISEED, X, INFO)
SLAROR
subroutine slarot (LROWS, LLEFT, LRIGHT, NL, C, S, A, LDA, XLEFT, XRIGHT)
SLAROT
subroutine slatm1 (MODE, COND, IRSIGN, IDIST, ISEED, D, N, INFO)
SLATM1
real function slatm2 (M, N, I, J, KL, KU, IDIST, ISEED, D, IGRADE, DL, DR, IPVTNG, IWORK, SPARSE)
SLATM2
real function slatm3 (M, N, I, J, ISUB, JSUB, KL, KU, IDIST, ISEED, D, IGRADE, DL, DR, IPVTNG, IWORK, SPARSE)
SLATM3
subroutine slatm5 (PRTYPE, M, N, A, LDA, B, LDB, C, LDC, D, LDD, E, LDE, F, LDF, R, LDR, L, LDL, ALPHA, QBLCKA, QBLCKB)
SLATM5
subroutine slatm6 (TYPE, N, A, LDA, B, X, LDX, Y, LDY, ALPHA, BETA, WX, WY, S, DIF)
SLATM6
subroutine slatm7 (MODE, COND, IRSIGN, IDIST, ISEED, D, N, RANK, INFO)
SLATM7
subroutine slatme (N, DIST, ISEED, D, MODE, COND, DMAX, EI, RSIGN, UPPER, SIM, DS, MODES, CONDS, KL, KU, ANORM, A, LDA, WORK, INFO)
SLATME
subroutine slatmr (M, N, DIST, ISEED, SYM, D, MODE, COND, DMAX, RSIGN, GRADE, DL, MODEL, CONDL, DR, MODER, CONDR, PIVTNG, IPIVOT, KL, KU, SPARSE, ANORM, PACK, A, LDA, IWORK, INFO)
SLATMR
subroutine slatms (M, N, DIST, ISEED, SYM, D, MODE, COND, DMAX, KL, KU, PACK, A, LDA, WORK, INFO)
SLATMS
subroutine slatmt (M, N, DIST, ISEED, SYM, D, MODE, COND, DMAX, RANK, KL, KU, PACK, A, LDA, WORK, INFO)
SLATMT
Detailed Description
This is the group of real LAPACK TESTING MATGEN routines.
Function Documentation
subroutine slagge (integer M, integer N, integer KL, integer KU, real, dimension( * ) D, real, dimension( lda, * ) A, integer LDA, integer, dimension( 4 ) ISEED, real, dimension( * ) WORK, integer INFO)
SLAGGE
Purpose:

SLAGGE generates a real general m by n matrix A, by pre and post multiplying a real diagonal matrix D with random orthogonal matrices: A = U*D*V. The lower and upper bandwidths may then be reduced to kl and ku by additional orthogonal transformations.
Parameters:

M
M is INTEGER The number of rows of the matrix A. M >= 0.
NN is INTEGER The number of columns of the matrix A. N >= 0.
KLKL is INTEGER The number of nonzero subdiagonals within the band of A. 0 <= KL <= M1.
KUKU is INTEGER The number of nonzero superdiagonals within the band of A. 0 <= KU <= N1.
DD is REAL array, dimension (min(M,N)) The diagonal elements of the diagonal matrix D.
AA is REAL array, dimension (LDA,N) The generated m by n matrix A.
LDALDA is INTEGER The leading dimension of the array A. LDA >= M.
ISEEDISEED is INTEGER array, dimension (4) On entry, the seed of the random number generator; the array elements must be between 0 and 4095, and ISEED(4) must be odd. On exit, the seed is updated.
WORKWORK is REAL array, dimension (M+N)
INFOINFO is INTEGER = 0: successful exit < 0: if INFO = i, the ith argument had an illegal value
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2015
subroutine slagsy (integer N, integer K, real, dimension( * ) D, real, dimension( lda, * ) A, integer LDA, integer, dimension( 4 ) ISEED, real, dimension( * ) WORK, integer INFO)
SLAGSY
Purpose:

SLAGSY generates a real symmetric matrix A, by pre and post multiplying a real diagonal matrix D with a random orthogonal matrix: A = U*D*U'. The semibandwidth may then be reduced to k by additional orthogonal transformations.
Parameters:

N
N is INTEGER The order of the matrix A. N >= 0.
KK is INTEGER The number of nonzero subdiagonals within the band of A. 0 <= K <= N1.
DD is REAL array, dimension (N) The diagonal elements of the diagonal matrix D.
AA is REAL array, dimension (LDA,N) The generated n by n symmetric matrix A (the full matrix is stored).
LDALDA is INTEGER The leading dimension of the array A. LDA >= N.
ISEEDISEED is INTEGER array, dimension (4) On entry, the seed of the random number generator; the array elements must be between 0 and 4095, and ISEED(4) must be odd. On exit, the seed is updated.
WORKWORK is REAL array, dimension (2*N)
INFOINFO is INTEGER = 0: successful exit < 0: if INFO = i, the ith argument had an illegal value
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
subroutine slahilb (integer N, integer NRHS, real, dimension(lda, n) A, integer LDA, real, dimension(ldx, nrhs) X, integer LDX, real, dimension(ldb, nrhs) B, integer LDB, real, dimension(n) WORK, integer INFO)
SLAHILB
Purpose:

SLAHILB generates an N by N scaled Hilbert matrix in A along with NRHS righthand sides in B and solutions in X such that A*X=B. The Hilbert matrix is scaled by M = LCM(1, 2, ..., 2*N1) so that all entries are integers. The righthand sides are the first NRHS columns of M * the identity matrix, and the solutions are the first NRHS columns of the inverse Hilbert matrix. The condition number of the Hilbert matrix grows exponentially with its size, roughly as O(e ** (3.5*N)). Additionally, the inverse Hilbert matrices beyond a relatively small dimension cannot be generated exactly without extra precision. Precision is exhausted when the largest entry in the inverse Hilbert matrix is greater than 2 to the power of the number of bits in the fraction of the data type used plus one, which is 24 for single precision. In single, the generated solution is exact for N <= 6 and has small componentwise error for 7 <= N <= 11.
Parameters:

N
N is INTEGER The dimension of the matrix A.
NRHSNRHS is INTEGER The requested number of righthand sides.
AA is REAL array, dimension (LDA, N) The generated scaled Hilbert matrix.
LDALDA is INTEGER The leading dimension of the array A. LDA >= N.
XX is REAL array, dimension (LDX, NRHS) The generated exact solutions. Currently, the first NRHS columns of the inverse Hilbert matrix.
LDXLDX is INTEGER The leading dimension of the array X. LDX >= N.
BB is REAL array, dimension (LDB, NRHS) The generated righthand sides. Currently, the first NRHS columns of LCM(1, 2, ..., 2*N1) * the identity matrix.
LDBLDB is INTEGER The leading dimension of the array B. LDB >= N.
WORKWORK is REAL array, dimension (N)
INFOINFO is INTEGER = 0: successful exit = 1: N is too large; the data is still generated but may not be not exact. < 0: if INFO = i, the ith argument had an illegal value
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2015
subroutine slakf2 (integer M, integer N, real, dimension( lda, * ) A, integer LDA, real, dimension( lda, * ) B, real, dimension( lda, * ) D, real, dimension( lda, * ) E, real, dimension( ldz, * ) Z, integer LDZ)
SLAKF2
Purpose:

Form the 2*M*N by 2*M*N matrix Z = [ kron(In, A) kron(B', Im) ] [ kron(In, D) kron(E', Im) ], where In is the identity matrix of size n and X' is the transpose of X. kron(X, Y) is the Kronecker product between the matrices X and Y.
Parameters:

M
M is INTEGER Size of matrix, must be >= 1.
NN is INTEGER Size of matrix, must be >= 1.
AA is REAL, dimension ( LDA, M ) The matrix A in the output matrix Z.
LDALDA is INTEGER The leading dimension of A, B, D, and E. ( LDA >= M+N )
BB is REAL, dimension ( LDA, N )
DD is REAL, dimension ( LDA, M )
EE is REAL, dimension ( LDA, N ) The matrices used in forming the output matrix Z.
ZZ is REAL, dimension ( LDZ, 2*M*N ) The resultant Kronecker M*N*2 by M*N*2 matrix (see above.)
LDZLDZ is INTEGER The leading dimension of Z. ( LDZ >= 2*M*N )
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
real function slaran (integer, dimension( 4 ) ISEED)
SLARAN
Purpose:

SLARAN returns a random real number from a uniform (0,1) distribution.
Parameters:

ISEED
ISEED is INTEGER array, dimension (4) On entry, the seed of the random number generator; the array elements must be between 0 and 4095, and ISEED(4) must be odd. On exit, the seed is updated.
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
Further Details:

This routine uses a multiplicative congruential method with modulus 2**48 and multiplier 33952834046453 (see G.S.Fishman, 'Multiplicative congruential random number generators with modulus 2**b: an exhaustive analysis for b = 32 and a partial analysis for b = 48', Math. Comp. 189, pp 331344, 1990). 48bit integers are stored in 4 integer array elements with 12 bits per element. Hence the routine is portable across machines with integers of 32 bits or more.
subroutine slarge (integer N, real, dimension( lda, * ) A, integer LDA, integer, dimension( 4 ) ISEED, real, dimension( * ) WORK, integer INFO)
SLARGE
Purpose:

SLARGE pre and postmultiplies a real general n by n matrix A with a random orthogonal matrix: A = U*D*U'.
Parameters:

N
N is INTEGER The order of the matrix A. N >= 0.
AA is REAL array, dimension (LDA,N) On entry, the original n by n matrix A. On exit, A is overwritten by U*A*U' for some random orthogonal matrix U.
LDALDA is INTEGER The leading dimension of the array A. LDA >= N.
ISEEDISEED is INTEGER array, dimension (4) On entry, the seed of the random number generator; the array elements must be between 0 and 4095, and ISEED(4) must be odd. On exit, the seed is updated.
WORKWORK is REAL array, dimension (2*N)
INFOINFO is INTEGER = 0: successful exit < 0: if INFO = i, the ith argument had an illegal value
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
real function slarnd (integer IDIST, integer, dimension( 4 ) ISEED)
SLARND
Purpose:

SLARND returns a random real number from a uniform or normal distribution.
Parameters:

IDIST
IDIST is INTEGER Specifies the distribution of the random numbers: = 1: uniform (0,1) = 2: uniform (1,1) = 3: normal (0,1)
ISEEDISEED is INTEGER array, dimension (4) On entry, the seed of the random number generator; the array elements must be between 0 and 4095, and ISEED(4) must be odd. On exit, the seed is updated.
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
Further Details:

This routine calls the auxiliary routine SLARAN to generate a random real number from a uniform (0,1) distribution. The BoxMuller method is used to transform numbers from a uniform to a normal distribution.
subroutine slaror (character SIDE, character INIT, integer M, integer N, real, dimension( lda, * ) A, integer LDA, integer, dimension( 4 ) ISEED, real, dimension( * ) X, integer INFO)
SLAROR
Purpose:

SLAROR pre or postmultiplies an M by N matrix A by a random orthogonal matrix U, overwriting A. A may optionally be initialized to the identity matrix before multiplying by U. U is generated using the method of G.W. Stewart (SIAM J. Numer. Anal. 17, 1980, 403409).
Parameters:

SIDE
SIDE is CHARACTER*1 Specifies whether A is multiplied on the left or right by U. = 'L': Multiply A on the left (premultiply) by U = 'R': Multiply A on the right (postmultiply) by U' = 'C' or 'T': Multiply A on the left by U and the right by U' (Here, U' means Utranspose.)
INITINIT is CHARACTER*1 Specifies whether or not A should be initialized to the identity matrix. = 'I': Initialize A to (a section of) the identity matrix before applying U. = 'N': No initialization. Apply U to the input matrix A. INIT = 'I' may be used to generate square or rectangular orthogonal matrices: For M = N and SIDE = 'L' or 'R', the rows will be orthogonal to each other, as will the columns. If M < N, SIDE = 'R' produces a dense matrix whose rows are orthogonal and whose columns are not, while SIDE = 'L' produces a matrix whose rows are orthogonal, and whose first M columns are orthogonal, and whose remaining columns are zero. If M > N, SIDE = 'L' produces a dense matrix whose columns are orthogonal and whose rows are not, while SIDE = 'R' produces a matrix whose columns are orthogonal, and whose first M rows are orthogonal, and whose remaining rows are zero.
MM is INTEGER The number of rows of A.
NN is INTEGER The number of columns of A.
AA is REAL array, dimension (LDA, N) On entry, the array A. On exit, overwritten by U A ( if SIDE = 'L' ), or by A U ( if SIDE = 'R' ), or by U A U' ( if SIDE = 'C' or 'T').
LDALDA is INTEGER The leading dimension of the array A. LDA >= max(1,M).
ISEEDISEED is INTEGER array, dimension (4) On entry ISEED specifies the seed of the random number generator. The array elements should be between 0 and 4095; if not they will be reduced mod 4096. Also, ISEED(4) must be odd. The random number generator uses a linear congruential sequence limited to small integers, and so should produce machine independent random numbers. The values of ISEED are changed on exit, and can be used in the next call to SLAROR to continue the same random number sequence.
XX is REAL array, dimension (3*MAX( M, N )) Workspace of length 2*M + N if SIDE = 'L', 2*N + M if SIDE = 'R', 3*N if SIDE = 'C' or 'T'.
INFOINFO is INTEGER An error flag. It is set to: = 0: normal return < 0: if INFO = k, the kth argument had an illegal value = 1: if the random numbers generated by SLARND are bad.
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
subroutine slarot (logical LROWS, logical LLEFT, logical LRIGHT, integer NL, real C, real S, real, dimension( * ) A, integer LDA, real XLEFT, real XRIGHT)
SLAROT
Purpose:

SLAROT applies a (Givens) rotation to two adjacent rows or columns, where one element of the first and/or last column/row for use on matrices stored in some format other than GE, so that elements of the matrix may be used or modified for which no array element is provided. One example is a symmetric matrix in SB format (bandwidth=4), for which UPLO='L': Two adjacent rows will have the format: row j: C> C> C> C> C> . . . . row j+1: C> C> C> C> C> . . . . '*' indicates elements for which storage is provided, '.' indicates elements for which no storage is provided, but are not necessarily zero; their values are determined by symmetry. ' ' indicates elements which are necessarily zero, and have no storage provided. Those columns which have two '*'s can be handled by SROT. Those columns which have no '*'s can be ignored, since as long as the Givens rotations are carefully applied to preserve symmetry, their values are determined. Those columns which have one '*' have to be handled separately, by using separate variables "p" and "q": row j: C> C> C> C> C> p . . . row j+1: q C> C> C> C> C> . . . . The element p would have to be set correctly, then that column is rotated, setting p to its new value. The next call to SLAROT would rotate columns j and j+1, using p, and restore symmetry. The element q would start out being zero, and be made nonzero by the rotation. Later, rotations would presumably be chosen to zero q out. Typical Calling Sequences: rotating the ith and (i+1)st rows.    General dense matrix: CALL SLAROT(.TRUE.,.FALSE.,.FALSE., N, C,S, A(i,1),LDA, DUMMY, DUMMY) General banded matrix in GB format: j = MAX(1, iKL ) NL = MIN( N, i+KU+1 ) + 1j CALL SLAROT( .TRUE., iKL.GE.1, i+KU.LT.N, NL, C,S, A(KU+i+1j,j),LDA1, XLEFT, XRIGHT ) [ note that i+1j is just MIN(i,KL+1) ] Symmetric banded matrix in SY format, bandwidth K, lower triangle only: j = MAX(1, iK ) NL = MIN( K+1, i ) + 1 CALL SLAROT( .TRUE., iK.GE.1, .TRUE., NL, C,S, A(i,j), LDA, XLEFT, XRIGHT ) Same, but upper triangle only: NL = MIN( K+1, Ni ) + 1 CALL SLAROT( .TRUE., .TRUE., i+K.LT.N, NL, C,S, A(i,i), LDA, XLEFT, XRIGHT ) Symmetric banded matrix in SB format, bandwidth K, lower triangle only: [ same as for SY, except:] . . . . A(i+1j,j), LDA1, XLEFT, XRIGHT ) [ note that i+1j is just MIN(i,K+1) ] Same, but upper triangle only: . . . A(K+1,i), LDA1, XLEFT, XRIGHT ) Rotating columns is just the transpose of rotating rows, except for GB and SB: (rotating columns i and i+1) GB: j = MAX(1, iKU ) NL = MIN( N, i+KL+1 ) + 1j CALL SLAROT( .TRUE., iKU.GE.1, i+KL.LT.N, NL, C,S, A(KU+j+1i,i),LDA1, XTOP, XBOTTM ) [note that KU+j+1i is just MAX(1,KU+2i)] SB: (upper triangle) . . . . . . A(K+j+1i,i),LDA1, XTOP, XBOTTM ) SB: (lower triangle) . . . . . . A(1,i),LDA1, XTOP, XBOTTM )
LROWS  LOGICAL If .TRUE., then SLAROT will rotate two rows. If .FALSE., then it will rotate two columns. Not modified. LLEFT  LOGICAL If .TRUE., then XLEFT will be used instead of the corresponding element of A for the first element in the second row (if LROWS=.FALSE.) or column (if LROWS=.TRUE.) If .FALSE., then the corresponding element of A will be used. Not modified. LRIGHT  LOGICAL If .TRUE., then XRIGHT will be used instead of the corresponding element of A for the last element in the first row (if LROWS=.FALSE.) or column (if LROWS=.TRUE.) If .FALSE., then the corresponding element of A will be used. Not modified. NL  INTEGER The length of the rows (if LROWS=.TRUE.) or columns (if LROWS=.FALSE.) to be rotated. If XLEFT and/or XRIGHT are used, the columns/rows they are in should be included in NL, e.g., if LLEFT = LRIGHT = .TRUE., then NL must be at least 2. The number of rows/columns to be rotated exclusive of those involving XLEFT and/or XRIGHT may not be negative, i.e., NL minus how many of LLEFT and LRIGHT are .TRUE. must be at least zero; if not, XERBLA will be called. Not modified. C, S  REAL Specify the Givens rotation to be applied. If LROWS is true, then the matrix ( c s ) (s c ) is applied from the left; if false, then the transpose thereof is applied from the right. For a Givens rotation, C**2 + S**2 should be 1, but this is not checked. Not modified. A  REAL array. The array containing the rows/columns to be rotated. The first element of A should be the upper left element to be rotated. Read and modified. LDA  INTEGER The "effective" leading dimension of A. If A contains a matrix stored in GE or SY format, then this is just the leading dimension of A as dimensioned in the calling routine. If A contains a matrix stored in band (GB or SB) format, then this should be *one less* than the leading dimension used in the calling routine. Thus, if A were dimensioned A(LDA,*) in SLAROT, then A(1,j) would be the jth element in the first of the two rows to be rotated, and A(2,j) would be the jth in the second, regardless of how the array may be stored in the calling routine. [A cannot, however, actually be dimensioned thus, since for band format, the row number may exceed LDA, which is not legal FORTRAN.] If LROWS=.TRUE., then LDA must be at least 1, otherwise it must be at least NL minus the number of .TRUE. values in XLEFT and XRIGHT. Not modified. XLEFT  REAL If LLEFT is .TRUE., then XLEFT will be used and modified instead of A(2,1) (if LROWS=.TRUE.) or A(1,2) (if LROWS=.FALSE.). Read and modified. XRIGHT  REAL If LRIGHT is .TRUE., then XRIGHT will be used and modified instead of A(1,NL) (if LROWS=.TRUE.) or A(NL,1) (if LROWS=.FALSE.). Read and modified.
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
subroutine slatm1 (integer MODE, real COND, integer IRSIGN, integer IDIST, integer, dimension( 4 ) ISEED, real, dimension( * ) D, integer N, integer INFO)
SLATM1
Purpose:

SLATM1 computes the entries of D(1..N) as specified by MODE, COND and IRSIGN. IDIST and ISEED determine the generation of random numbers. SLATM1 is called by SLATMR to generate random test matrices for LAPACK programs.
Parameters:

MODE
MODE is INTEGER On entry describes how D is to be computed: MODE = 0 means do not change D. MODE = 1 sets D(1)=1 and D(2:N)=1.0/COND MODE = 2 sets D(1:N1)=1 and D(N)=1.0/COND MODE = 3 sets D(I)=COND**((I1)/(N1)) MODE = 4 sets D(i)=1  (i1)/(N1)*(1  1/COND) MODE = 5 sets D to random numbers in the range ( 1/COND , 1 ) such that their logarithms are uniformly distributed. MODE = 6 set D to random numbers from same distribution as the rest of the matrix. MODE < 0 has the same meaning as ABS(MODE), except that the order of the elements of D is reversed. Thus if MODE is positive, D has entries ranging from 1 to 1/COND, if negative, from 1/COND to 1, Not modified.
CONDCOND is REAL On entry, used as described under MODE above. If used, it must be >= 1. Not modified.
IRSIGNIRSIGN is INTEGER On entry, if MODE neither 6, 0 nor 6, determines sign of entries of D 0 => leave entries of D unchanged 1 => multiply each entry of D by 1 or 1 with probability .5
IDISTIDIST is INTEGER On entry, IDIST specifies the type of distribution to be used to generate a random matrix . 1 => UNIFORM( 0, 1 ) 2 => UNIFORM( 1, 1 ) 3 => NORMAL( 0, 1 ) Not modified.
ISEEDISEED is INTEGER array, dimension ( 4 ) On entry ISEED specifies the seed of the random number generator. The random number generator uses a linear congruential sequence limited to small integers, and so should produce machine independent random numbers. The values of ISEED are changed on exit, and can be used in the next call to SLATM1 to continue the same random number sequence. Changed on exit.
DD is REAL array, dimension ( N ) Array to be computed according to MODE, COND and IRSIGN. May be changed on exit if MODE is nonzero.
NN is INTEGER Number of entries of D. Not modified.
INFOINFO is INTEGER 0 => normal termination 1 => if MODE not in range 6 to 6 2 => if MODE neither 6, 0 nor 6, and IRSIGN neither 0 nor 1 3 => if MODE neither 6, 0 nor 6 and COND less than 1 4 => if MODE equals 6 or 6 and IDIST not in range 1 to 3 7 => if N negative
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2015
real function slatm2 (integer M, integer N, integer I, integer J, integer KL, integer KU, integer IDIST, integer, dimension( 4 ) ISEED, real, dimension( * ) D, integer IGRADE, real, dimension( * ) DL, real, dimension( * ) DR, integer IPVTNG, integer, dimension( * ) IWORK, real SPARSE)
SLATM2
Purpose:

SLATM2 returns the (I,J) entry of a random matrix of dimension (M, N) described by the other parameters. It is called by the SLATMR routine in order to build random test matrices. No error checking on parameters is done, because this routine is called in a tight loop by SLATMR which has already checked the parameters. Use of SLATM2 differs from SLATM3 in the order in which the random number generator is called to fill in random matrix entries. With SLATM2, the generator is called to fill in the pivoted matrix columnwise. With SLATM3, the generator is called to fill in the matrix columnwise, after which it is pivoted. Thus, SLATM3 can be used to construct random matrices which differ only in their order of rows and/or columns. SLATM2 is used to construct band matrices while avoiding calling the random number generator for entries outside the band (and therefore generating random numbers The matrix whose (I,J) entry is returned is constructed as follows (this routine only computes one entry): If I is outside (1..M) or J is outside (1..N), return zero (this is convenient for generating matrices in band format). Generate a matrix A with random entries of distribution IDIST. Set the diagonal to D. Grade the matrix, if desired, from the left (by DL) and/or from the right (by DR or DL) as specified by IGRADE. Permute, if desired, the rows and/or columns as specified by IPVTNG and IWORK. Band the matrix to have lower bandwidth KL and upper bandwidth KU. Set random entries to zero as specified by SPARSE.
Parameters:

M
M is INTEGER Number of rows of matrix. Not modified.
NN is INTEGER Number of columns of matrix. Not modified.
II is INTEGER Row of entry to be returned. Not modified.
JJ is INTEGER Column of entry to be returned. Not modified.
KLKL is INTEGER Lower bandwidth. Not modified.
KUKU is INTEGER Upper bandwidth. Not modified.
IDISTIDIST is INTEGER On entry, IDIST specifies the type of distribution to be used to generate a random matrix . 1 => UNIFORM( 0, 1 ) 2 => UNIFORM( 1, 1 ) 3 => NORMAL( 0, 1 ) Not modified.
ISEEDISEED is INTEGER array of dimension ( 4 ) Seed for random number generator. Changed on exit.
DD is REAL array of dimension ( MIN( I , J ) ) Diagonal entries of matrix. Not modified.
IGRADEIGRADE is INTEGER Specifies grading of matrix as follows: 0 => no grading 1 => matrix premultiplied by diag( DL ) 2 => matrix postmultiplied by diag( DR ) 3 => matrix premultiplied by diag( DL ) and postmultiplied by diag( DR ) 4 => matrix premultiplied by diag( DL ) and postmultiplied by inv( diag( DL ) ) 5 => matrix premultiplied by diag( DL ) and postmultiplied by diag( DL ) Not modified.
DLDL is REAL array ( I or J, as appropriate ) Left scale factors for grading matrix. Not modified.
DRDR is REAL array ( I or J, as appropriate ) Right scale factors for grading matrix. Not modified.
IPVTNGIPVTNG is INTEGER On entry specifies pivoting permutations as follows: 0 => none. 1 => row pivoting. 2 => column pivoting. 3 => full pivoting, i.e., on both sides. Not modified.
IWORKIWORK is INTEGER array ( I or J, as appropriate ) This array specifies the permutation used. The row (or column) in position K was originally in position IWORK( K ). This differs from IWORK for SLATM3. Not modified.
SPARSESPARSE is REAL between 0. and 1. On entry specifies the sparsity of the matrix if sparse matix is to be generated. SPARSE should lie between 0 and 1. A uniform ( 0, 1 ) random number x is generated and compared to SPARSE; if x is larger the matrix entry is unchanged and if x is smaller the entry is set to zero. Thus on the average a fraction SPARSE of the entries will be set to zero. Not modified.
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 June 2016
real function slatm3 (integer M, integer N, integer I, integer J, integer ISUB, integer JSUB, integer KL, integer KU, integer IDIST, integer, dimension( 4 ) ISEED, real, dimension( * ) D, integer IGRADE, real, dimension( * ) DL, real, dimension( * ) DR, integer IPVTNG, integer, dimension( * ) IWORK, real SPARSE)
SLATM3
Purpose:

SLATM3 returns the (ISUB,JSUB) entry of a random matrix of dimension (M, N) described by the other parameters. (ISUB,JSUB) is the final position of the (I,J) entry after pivoting according to IPVTNG and IWORK. SLATM3 is called by the SLATMR routine in order to build random test matrices. No error checking on parameters is done, because this routine is called in a tight loop by SLATMR which has already checked the parameters. Use of SLATM3 differs from SLATM2 in the order in which the random number generator is called to fill in random matrix entries. With SLATM2, the generator is called to fill in the pivoted matrix columnwise. With SLATM3, the generator is called to fill in the matrix columnwise, after which it is pivoted. Thus, SLATM3 can be used to construct random matrices which differ only in their order of rows and/or columns. SLATM2 is used to construct band matrices while avoiding calling the random number generator for entries outside the band (and therefore generating random numbers in different orders for different pivot orders). The matrix whose (ISUB,JSUB) entry is returned is constructed as follows (this routine only computes one entry): If ISUB is outside (1..M) or JSUB is outside (1..N), return zero (this is convenient for generating matrices in band format). Generate a matrix A with random entries of distribution IDIST. Set the diagonal to D. Grade the matrix, if desired, from the left (by DL) and/or from the right (by DR or DL) as specified by IGRADE. Permute, if desired, the rows and/or columns as specified by IPVTNG and IWORK. Band the matrix to have lower bandwidth KL and upper bandwidth KU. Set random entries to zero as specified by SPARSE.
Parameters:

M
M is INTEGER Number of rows of matrix. Not modified.
NN is INTEGER Number of columns of matrix. Not modified.
II is INTEGER Row of unpivoted entry to be returned. Not modified.
JJ is INTEGER Column of unpivoted entry to be returned. Not modified.
ISUBISUB is INTEGER Row of pivoted entry to be returned. Changed on exit.
JSUBJSUB is INTEGER Column of pivoted entry to be returned. Changed on exit.
KLKL is INTEGER Lower bandwidth. Not modified.
KUKU is INTEGER Upper bandwidth. Not modified.
IDISTIDIST is INTEGER On entry, IDIST specifies the type of distribution to be used to generate a random matrix . 1 => UNIFORM( 0, 1 ) 2 => UNIFORM( 1, 1 ) 3 => NORMAL( 0, 1 ) Not modified.
ISEEDISEED is INTEGER array of dimension ( 4 ) Seed for random number generator. Changed on exit.
DD is REAL array of dimension ( MIN( I , J ) ) Diagonal entries of matrix. Not modified.
IGRADEIGRADE is INTEGER Specifies grading of matrix as follows: 0 => no grading 1 => matrix premultiplied by diag( DL ) 2 => matrix postmultiplied by diag( DR ) 3 => matrix premultiplied by diag( DL ) and postmultiplied by diag( DR ) 4 => matrix premultiplied by diag( DL ) and postmultiplied by inv( diag( DL ) ) 5 => matrix premultiplied by diag( DL ) and postmultiplied by diag( DL ) Not modified.
DLDL is REAL array ( I or J, as appropriate ) Left scale factors for grading matrix. Not modified.
DRDR is REAL array ( I or J, as appropriate ) Right scale factors for grading matrix. Not modified.
IPVTNGIPVTNG is INTEGER On entry specifies pivoting permutations as follows: 0 => none. 1 => row pivoting. 2 => column pivoting. 3 => full pivoting, i.e., on both sides. Not modified.
IWORKIWORK is INTEGER array ( I or J, as appropriate ) This array specifies the permutation used. The row (or column) originally in position K is in position IWORK( K ) after pivoting. This differs from IWORK for SLATM2. Not modified.
SPARSESPARSE is REAL between 0. and 1. On entry specifies the sparsity of the matrix if sparse matix is to be generated. SPARSE should lie between 0 and 1. A uniform ( 0, 1 ) random number x is generated and compared to SPARSE; if x is larger the matrix entry is unchanged and if x is smaller the entry is set to zero. Thus on the average a fraction SPARSE of the entries will be set to zero. Not modified.
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 June 2016
subroutine slatm5 (integer PRTYPE, integer M, integer N, real, dimension( lda, * ) A, integer LDA, real, dimension( ldb, * ) B, integer LDB, real, dimension( ldc, * ) C, integer LDC, real, dimension( ldd, * ) D, integer LDD, real, dimension( lde, * ) E, integer LDE, real, dimension( ldf, * ) F, integer LDF, real, dimension( ldr, * ) R, integer LDR, real, dimension( ldl, * ) L, integer LDL, real ALPHA, integer QBLCKA, integer QBLCKB)
SLATM5
Purpose:

SLATM5 generates matrices involved in the Generalized Sylvester equation: A * R  L * B = C D * R  L * E = F They also satisfy (the diagonalization condition) [ I L ] ( [ A C ], [ D F ] ) [ I R ] = ( [ A ], [ D ] ) [ I ] ( [ B ] [ E ] ) [ I ] ( [ B ] [ E ] )
Parameters:

PRTYPE
PRTYPE is INTEGER "Points" to a certain type of the matrices to generate (see further details).
MM is INTEGER Specifies the order of A and D and the number of rows in C, F, R and L.
NN is INTEGER Specifies the order of B and E and the number of columns in C, F, R and L.
AA is REAL array, dimension (LDA, M). On exit A MbyM is initialized according to PRTYPE.
LDALDA is INTEGER The leading dimension of A.
BB is REAL array, dimension (LDB, N). On exit B NbyN is initialized according to PRTYPE.
LDBLDB is INTEGER The leading dimension of B.
CC is REAL array, dimension (LDC, N). On exit C MbyN is initialized according to PRTYPE.
LDCLDC is INTEGER The leading dimension of C.
DD is REAL array, dimension (LDD, M). On exit D MbyM is initialized according to PRTYPE.
LDDLDD is INTEGER The leading dimension of D.
EE is REAL array, dimension (LDE, N). On exit E NbyN is initialized according to PRTYPE.
LDELDE is INTEGER The leading dimension of E.
FF is REAL array, dimension (LDF, N). On exit F MbyN is initialized according to PRTYPE.
LDFLDF is INTEGER The leading dimension of F.
RR is REAL array, dimension (LDR, N). On exit R MbyN is initialized according to PRTYPE.
LDRLDR is INTEGER The leading dimension of R.
LL is REAL array, dimension (LDL, N). On exit L MbyN is initialized according to PRTYPE.
LDLLDL is INTEGER The leading dimension of L.
ALPHAALPHA is REAL Parameter used in generating PRTYPE = 1 and 5 matrices.
QBLCKAQBLCKA is INTEGER When PRTYPE = 3, specifies the distance between 2by2 blocks on the diagonal in A. Otherwise, QBLCKA is not referenced. QBLCKA > 1.
QBLCKBQBLCKB is INTEGER When PRTYPE = 3, specifies the distance between 2by2 blocks on the diagonal in B. Otherwise, QBLCKB is not referenced. QBLCKB > 1.
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 June 2016
Further Details:

PRTYPE = 1: A and B are Jordan blocks, D and E are identity matrices A : if (i == j) then A(i, j) = 1.0 if (j == i + 1) then A(i, j) = 1.0 else A(i, j) = 0.0, i, j = 1...M B : if (i == j) then B(i, j) = 1.0  ALPHA if (j == i + 1) then B(i, j) = 1.0 else B(i, j) = 0.0, i, j = 1...N D : if (i == j) then D(i, j) = 1.0 else D(i, j) = 0.0, i, j = 1...M E : if (i == j) then E(i, j) = 1.0 else E(i, j) = 0.0, i, j = 1...N L = R are chosen from [10...10], which specifies the right hand sides (C, F). PRTYPE = 2 or 3: Triangular and/or quasi triangular. A : if (i <= j) then A(i, j) = [1...1] else A(i, j) = 0.0, i, j = 1...M if (PRTYPE = 3) then A(k + 1, k + 1) = A(k, k) A(k + 1, k) = [1...1] sign(A(k, k + 1) = (sin(A(k + 1, k)) k = 1, M  1, QBLCKA B : if (i <= j) then B(i, j) = [1...1] else B(i, j) = 0.0, i, j = 1...N if (PRTYPE = 3) then B(k + 1, k + 1) = B(k, k) B(k + 1, k) = [1...1] sign(B(k, k + 1) = (sign(B(k + 1, k)) k = 1, N  1, QBLCKB D : if (i <= j) then D(i, j) = [1...1]. else D(i, j) = 0.0, i, j = 1...M E : if (i <= j) then D(i, j) = [1...1] else E(i, j) = 0.0, i, j = 1...N L, R are chosen from [10...10], which specifies the right hand sides (C, F). PRTYPE = 4 Full A(i, j) = [10...10] D(i, j) = [1...1] i,j = 1...M B(i, j) = [10...10] E(i, j) = [1...1] i,j = 1...N R(i, j) = [10...10] L(i, j) = [1...1] i = 1..M ,j = 1...N L, R specifies the right hand sides (C, F). PRTYPE = 5 special case common and/or close eigs.
subroutine slatm6 (integer TYPE, integer N, real, dimension( lda, * ) A, integer LDA, real, dimension( lda, * ) B, real, dimension( ldx, * ) X, integer LDX, real, dimension( ldy, * ) Y, integer LDY, real ALPHA, real BETA, real WX, real WY, real, dimension( * ) S, real, dimension( * ) DIF)
SLATM6
Purpose:

SLATM6 generates test matrices for the generalized eigenvalue problem, their corresponding right and left eigenvector matrices, and also reciprocal condition numbers for all eigenvalues and the reciprocal condition numbers of eigenvectors corresponding to the 1th and 5th eigenvalues. Test Matrices ============= Two kinds of test matrix pairs (A, B) = inverse(YH) * (Da, Db) * inverse(X) are used in the tests: Type 1: Da = 1+a 0 0 0 0 Db = 1 0 0 0 0 0 2+a 0 0 0 0 1 0 0 0 0 0 3+a 0 0 0 0 1 0 0 0 0 0 4+a 0 0 0 0 1 0 0 0 0 0 5+a , 0 0 0 0 1 , and Type 2: Da = 1 1 0 0 0 Db = 1 0 0 0 0 1 1 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 1+a 1+b 0 0 0 1 0 0 0 0 1b 1+a , 0 0 0 0 1 . In both cases the same inverse(YH) and inverse(X) are used to compute (A, B), giving the exact eigenvectors to (A,B) as (YH, X): YH: = 1 0 y y y X = 1 0 x x x 0 1 y y y 0 1 x x x 0 0 1 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 1, 0 0 0 0 1 , where a, b, x and y will have all values independently of each other.
Parameters:

TYPE
TYPE is INTEGER Specifies the problem type (see further details).
NN is INTEGER Size of the matrices A and B.
AA is REAL array, dimension (LDA, N). On exit A NbyN is initialized according to TYPE.
LDALDA is INTEGER The leading dimension of A and of B.
BB is REAL array, dimension (LDA, N). On exit B NbyN is initialized according to TYPE.
XX is REAL array, dimension (LDX, N). On exit X is the NbyN matrix of right eigenvectors.
LDXLDX is INTEGER The leading dimension of X.
YY is REAL array, dimension (LDY, N). On exit Y is the NbyN matrix of left eigenvectors.
LDYLDY is INTEGER The leading dimension of Y.
ALPHAALPHA is REAL
BETABETA is REAL Weighting constants for matrix A.
WXWX is REAL Constant for right eigenvector matrix.
WYWY is REAL Constant for left eigenvector matrix.
SS is REAL array, dimension (N) S(i) is the reciprocal condition number for eigenvalue i.
DIFDIF is REAL array, dimension (N) DIF(i) is the reciprocal condition number for eigenvector i.
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
subroutine slatm7 (integer MODE, real COND, integer IRSIGN, integer IDIST, integer, dimension( 4 ) ISEED, real, dimension( * ) D, integer N, integer RANK, integer INFO)
SLATM7
Purpose:

SLATM7 computes the entries of D as specified by MODE COND and IRSIGN. IDIST and ISEED determine the generation of random numbers. SLATM7 is called by SLATMT to generate random test matrices.
MODE  INTEGER On entry describes how D is to be computed: MODE = 0 means do not change D. MODE = 1 sets D(1)=1 and D(2:RANK)=1.0/COND MODE = 2 sets D(1:RANK1)=1 and D(RANK)=1.0/COND MODE = 3 sets D(I)=COND**((I1)/(RANK1)) I=1:RANK MODE = 4 sets D(i)=1  (i1)/(N1)*(1  1/COND) MODE = 5 sets D to random numbers in the range ( 1/COND , 1 ) such that their logarithms are uniformly distributed. MODE = 6 set D to random numbers from same distribution as the rest of the matrix. MODE < 0 has the same meaning as ABS(MODE), except that the order of the elements of D is reversed. Thus if MODE is positive, D has entries ranging from 1 to 1/COND, if negative, from 1/COND to 1, Not modified. COND  REAL On entry, used as described under MODE above. If used, it must be >= 1. Not modified. IRSIGN  INTEGER On entry, if MODE neither 6, 0 nor 6, determines sign of entries of D 0 => leave entries of D unchanged 1 => multiply each entry of D by 1 or 1 with probability .5 IDIST  CHARACTER*1 On entry, IDIST specifies the type of distribution to be used to generate a random matrix . 1 => UNIFORM( 0, 1 ) 2 => UNIFORM( 1, 1 ) 3 => NORMAL( 0, 1 ) Not modified. ISEED  INTEGER array, dimension ( 4 ) On entry ISEED specifies the seed of the random number generator. The random number generator uses a linear congruential sequence limited to small integers, and so should produce machine independent random numbers. The values of ISEED are changed on exit, and can be used in the next call to SLATM7 to continue the same random number sequence. Changed on exit. D  REAL array, dimension ( MIN( M , N ) ) Array to be computed according to MODE, COND and IRSIGN. May be changed on exit if MODE is nonzero. N  INTEGER Number of entries of D. Not modified. RANK  INTEGER The rank of matrix to be generated for modes 1,2,3 only. D( RANK+1:N ) = 0. Not modified. INFO  INTEGER 0 => normal termination 1 => if MODE not in range 6 to 6 2 => if MODE neither 6, 0 nor 6, and IRSIGN neither 0 nor 1 3 => if MODE neither 6, 0 nor 6 and COND less than 1 4 => if MODE equals 6 or 6 and IDIST not in range 1 to 3 7 => if N negative
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 September 2012
subroutine slatme (integer N, character DIST, integer, dimension( 4 ) ISEED, real, dimension( * ) D, integer MODE, real COND, real DMAX, character, dimension( * ) EI, character RSIGN, character UPPER, character SIM, real, dimension( * ) DS, integer MODES, real CONDS, integer KL, integer KU, real ANORM, real, dimension( lda, * ) A, integer LDA, real, dimension( * ) WORK, integer INFO)
SLATME
Purpose:

SLATME generates random nonsymmetric square matrices with specified eigenvalues for testing LAPACK programs. SLATME operates by applying the following sequence of operations: 1. Set the diagonal to D, where D may be input or computed according to MODE, COND, DMAX, and RSIGN as described below. 2. If complex conjugate pairs are desired (MODE=0 and EI(1)='R', or MODE=5), certain pairs of adjacent elements of D are interpreted as the real and complex parts of a complex conjugate pair; A thus becomes block diagonal, with 1x1 and 2x2 blocks. 3. If UPPER='T', the upper triangle of A is set to random values out of distribution DIST. 4. If SIM='T', A is multiplied on the left by a random matrix X, whose singular values are specified by DS, MODES, and CONDS, and on the right by X inverse. 5. If KL < N1, the lower bandwidth is reduced to KL using Householder transformations. If KU < N1, the upper bandwidth is reduced to KU. 6. If ANORM is not negative, the matrix is scaled to have maximumelementnorm ANORM. (Note: since the matrix cannot be reduced beyond Hessenberg form, no packing options are available.)
Parameters:

N
N is INTEGER The number of columns (or rows) of A. Not modified.
DISTDIST is CHARACTER*1 On entry, DIST specifies the type of distribution to be used to generate the random eigen/singular values, and for the upper triangle (see UPPER). 'U' => UNIFORM( 0, 1 ) ( 'U' for uniform ) 'S' => UNIFORM( 1, 1 ) ( 'S' for symmetric ) 'N' => NORMAL( 0, 1 ) ( 'N' for normal ) Not modified.
ISEEDISEED is INTEGER array, dimension ( 4 ) On entry ISEED specifies the seed of the random number generator. They should lie between 0 and 4095 inclusive, and ISEED(4) should be odd. The random number generator uses a linear congruential sequence limited to small integers, and so should produce machine independent random numbers. The values of ISEED are changed on exit, and can be used in the next call to SLATME to continue the same random number sequence. Changed on exit.
DD is REAL array, dimension ( N ) This array is used to specify the eigenvalues of A. If MODE=0, then D is assumed to contain the eigenvalues (but see the description of EI), otherwise they will be computed according to MODE, COND, DMAX, and RSIGN and placed in D. Modified if MODE is nonzero.
MODEMODE is INTEGER On entry this describes how the eigenvalues are to be specified: MODE = 0 means use D (with EI) as input MODE = 1 sets D(1)=1 and D(2:N)=1.0/COND MODE = 2 sets D(1:N1)=1 and D(N)=1.0/COND MODE = 3 sets D(I)=COND**((I1)/(N1)) MODE = 4 sets D(i)=1  (i1)/(N1)*(1  1/COND) MODE = 5 sets D to random numbers in the range ( 1/COND , 1 ) such that their logarithms are uniformly distributed. Each oddeven pair of elements will be either used as two real eigenvalues or as the real and imaginary part of a complex conjugate pair of eigenvalues; the choice of which is done is random, with 5050 probability, for each pair. MODE = 6 set D to random numbers from same distribution as the rest of the matrix. MODE < 0 has the same meaning as ABS(MODE), except that the order of the elements of D is reversed. Thus if MODE is between 1 and 4, D has entries ranging from 1 to 1/COND, if between 1 and 4, D has entries ranging from 1/COND to 1, Not modified.
CONDCOND is REAL On entry, this is used as described under MODE above. If used, it must be >= 1. Not modified.
DMAXDMAX is REAL If MODE is neither 6, 0 nor 6, the contents of D, as computed according to MODE and COND, will be scaled by DMAX / max(abs(D(i))). Note that DMAX need not be positive: if DMAX is negative (or zero), D will be scaled by a negative number (or zero). Not modified.
EIEI is CHARACTER*1 array, dimension ( N ) If MODE is 0, and EI(1) is not ' ' (space character), this array specifies which elements of D (on input) are real eigenvalues and which are the real and imaginary parts of a complex conjugate pair of eigenvalues. The elements of EI may then only have the values 'R' and 'I'. If EI(j)='R' and EI(j+1)='I', then the jth eigenvalue is CMPLX( D(j) , D(j+1) ), and the (j+1)th is the complex conjugate thereof. If EI(j)=EI(j+1)='R', then the jth eigenvalue is D(j) (i.e., real). EI(1) may not be 'I', nor may two adjacent elements of EI both have the value 'I'. If MODE is not 0, then EI is ignored. If MODE is 0 and EI(1)=' ', then the eigenvalues will all be real. Not modified.
RSIGNRSIGN is CHARACTER*1 If MODE is not 0, 6, or 6, and RSIGN='T', then the elements of D, as computed according to MODE and COND, will be multiplied by a random sign (+1 or 1). If RSIGN='F', they will not be. RSIGN may only have the values 'T' or 'F'. Not modified.
UPPERUPPER is CHARACTER*1 If UPPER='T', then the elements of A above the diagonal (and above the 2x2 diagonal blocks, if A has complex eigenvalues) will be set to random numbers out of DIST. If UPPER='F', they will not. UPPER may only have the values 'T' or 'F'. Not modified.
SIMSIM is CHARACTER*1 If SIM='T', then A will be operated on by a "similarity transform", i.e., multiplied on the left by a matrix X and on the right by X inverse. X = U S V, where U and V are random unitary matrices and S is a (diagonal) matrix of singular values specified by DS, MODES, and CONDS. If SIM='F', then A will not be transformed. Not modified.
DSDS is REAL array, dimension ( N ) This array is used to specify the singular values of X, in the same way that D specifies the eigenvalues of A. If MODE=0, the DS contains the singular values, which may not be zero. Modified if MODE is nonzero.
MODESMODES is INTEGER
CONDSCONDS is REAL Same as MODE and COND, but for specifying the diagonal of S. MODES=6 and +6 are not allowed (since they would result in randomly illconditioned eigenvalues.)
KLKL is INTEGER This specifies the lower bandwidth of the matrix. KL=1 specifies upper Hessenberg form. If KL is at least N1, then A will have full lower bandwidth. KL must be at least 1. Not modified.
KUKU is INTEGER This specifies the upper bandwidth of the matrix. KU=1 specifies lower Hessenberg form. If KU is at least N1, then A will have full upper bandwidth; if KU and KL are both at least N1, then A will be dense. Only one of KU and KL may be less than N1. KU must be at least 1. Not modified.
ANORMANORM is REAL If ANORM is not negative, then A will be scaled by a non negative real number to make the maximumelementnorm of A to be ANORM. Not modified.
AA is REAL array, dimension ( LDA, N ) On exit A is the desired test matrix. Modified.
LDALDA is INTEGER LDA specifies the first dimension of A as declared in the calling program. LDA must be at least N. Not modified.
WORKWORK is REAL array, dimension ( 3*N ) Workspace. Modified.
INFOINFO is INTEGER Error code. On exit, INFO will be set to one of the following values: 0 => normal return 1 => N negative 2 => DIST illegal string 5 => MODE not in range 6 to 6 6 => COND less than 1.0, and MODE neither 6, 0 nor 6 8 => EI(1) is not ' ' or 'R', EI(j) is not 'R' or 'I', or two adjacent elements of EI are 'I'. 9 => RSIGN is not 'T' or 'F' 10 => UPPER is not 'T' or 'F' 11 => SIM is not 'T' or 'F' 12 => MODES=0 and DS has a zero singular value. 13 => MODES is not in the range 5 to 5. 14 => MODES is nonzero and CONDS is less than 1. 15 => KL is less than 1. 16 => KU is less than 1, or KL and KU are both less than N1. 19 => LDA is less than N. 1 => Error return from SLATM1 (computing D) 2 => Cannot scale to DMAX (max. eigenvalue is 0) 3 => Error return from SLATM1 (computing DS) 4 => Error return from SLARGE 5 => Zero singular value from SLATM1.
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
subroutine slatmr (integer M, integer N, character DIST, integer, dimension( 4 ) ISEED, character SYM, real, dimension( * ) D, integer MODE, real COND, real DMAX, character RSIGN, character GRADE, real, dimension( * ) DL, integer MODEL, real CONDL, real, dimension( * ) DR, integer MODER, real CONDR, character PIVTNG, integer, dimension( * ) IPIVOT, integer KL, integer KU, real SPARSE, real ANORM, character PACK, real, dimension( lda, * ) A, integer LDA, integer, dimension( * ) IWORK, integer INFO)
SLATMR
Purpose:

SLATMR generates random matrices of various types for testing LAPACK programs. SLATMR operates by applying the following sequence of operations: Generate a matrix A with random entries of distribution DIST which is symmetric if SYM='S', and nonsymmetric if SYM='N'. Set the diagonal to D, where D may be input or computed according to MODE, COND, DMAX and RSIGN as described below. Grade the matrix, if desired, from the left and/or right as specified by GRADE. The inputs DL, MODEL, CONDL, DR, MODER and CONDR also determine the grading as described below. Permute, if desired, the rows and/or columns as specified by PIVTNG and IPIVOT. Set random entries to zero, if desired, to get a random sparse matrix as specified by SPARSE. Make A a band matrix, if desired, by zeroing out the matrix outside a band of lower bandwidth KL and upper bandwidth KU. Scale A, if desired, to have maximum entry ANORM. Pack the matrix if desired. Options specified by PACK are: no packing zero out upper half (if symmetric) zero out lower half (if symmetric) store the upper half columnwise (if symmetric or square upper triangular) store the lower half columnwise (if symmetric or square lower triangular) same as upper half rowwise if symmetric store the lower triangle in banded format (if symmetric) store the upper triangle in banded format (if symmetric) store the entire matrix in banded format Note: If two calls to SLATMR differ only in the PACK parameter, they will generate mathematically equivalent matrices. If two calls to SLATMR both have full bandwidth (KL = M1 and KU = N1), and differ only in the PIVTNG and PACK parameters, then the matrices generated will differ only in the order of the rows and/or columns, and otherwise contain the same data. This consistency cannot be and is not maintained with less than full bandwidth.
Parameters:

M
M is INTEGER Number of rows of A. Not modified.
NN is INTEGER Number of columns of A. Not modified.
DISTDIST is CHARACTER*1 On entry, DIST specifies the type of distribution to be used to generate a random matrix . 'U' => UNIFORM( 0, 1 ) ( 'U' for uniform ) 'S' => UNIFORM( 1, 1 ) ( 'S' for symmetric ) 'N' => NORMAL( 0, 1 ) ( 'N' for normal ) Not modified.
ISEEDISEED is INTEGER array, dimension (4) On entry ISEED specifies the seed of the random number generator. They should lie between 0 and 4095 inclusive, and ISEED(4) should be odd. The random number generator uses a linear congruential sequence limited to small integers, and so should produce machine independent random numbers. The values of ISEED are changed on exit, and can be used in the next call to SLATMR to continue the same random number sequence. Changed on exit.
SYMSYM is CHARACTER*1 If SYM='S' or 'H', generated matrix is symmetric. If SYM='N', generated matrix is nonsymmetric. Not modified.
DD is REAL array, dimension (min(M,N)) On entry this array specifies the diagonal entries of the diagonal of A. D may either be specified on entry, or set according to MODE and COND as described below. May be changed on exit if MODE is nonzero.
MODEMODE is INTEGER On entry describes how D is to be used: MODE = 0 means use D as input MODE = 1 sets D(1)=1 and D(2:N)=1.0/COND MODE = 2 sets D(1:N1)=1 and D(N)=1.0/COND MODE = 3 sets D(I)=COND**((I1)/(N1)) MODE = 4 sets D(i)=1  (i1)/(N1)*(1  1/COND) MODE = 5 sets D to random numbers in the range ( 1/COND , 1 ) such that their logarithms are uniformly distributed. MODE = 6 set D to random numbers from same distribution as the rest of the matrix. MODE < 0 has the same meaning as ABS(MODE), except that the order of the elements of D is reversed. Thus if MODE is positive, D has entries ranging from 1 to 1/COND, if negative, from 1/COND to 1, Not modified.
CONDCOND is REAL On entry, used as described under MODE above. If used, it must be >= 1. Not modified.
DMAXDMAX is REAL If MODE neither 6, 0 nor 6, the diagonal is scaled by DMAX / max(abs(D(i))), so that maximum absolute entry of diagonal is abs(DMAX). If DMAX is negative (or zero), diagonal will be scaled by a negative number (or zero).
RSIGNRSIGN is CHARACTER*1 If MODE neither 6, 0 nor 6, specifies sign of diagonal as follows: 'T' => diagonal entries are multiplied by 1 or 1 with probability .5 'F' => diagonal unchanged Not modified.
GRADEGRADE is CHARACTER*1 Specifies grading of matrix as follows: 'N' => no grading 'L' => matrix premultiplied by diag( DL ) (only if matrix nonsymmetric) 'R' => matrix postmultiplied by diag( DR ) (only if matrix nonsymmetric) 'B' => matrix premultiplied by diag( DL ) and postmultiplied by diag( DR ) (only if matrix nonsymmetric) 'S' or 'H' => matrix premultiplied by diag( DL ) and postmultiplied by diag( DL ) ('S' for symmetric, or 'H' for Hermitian) 'E' => matrix premultiplied by diag( DL ) and postmultiplied by inv( diag( DL ) ) ( 'E' for eigenvalue invariance) (only if matrix nonsymmetric) Note: if GRADE='E', then M must equal N. Not modified.
DLDL is REAL array, dimension (M) If MODEL=0, then on entry this array specifies the diagonal entries of a diagonal matrix used as described under GRADE above. If MODEL is not zero, then DL will be set according to MODEL and CONDL, analogous to the way D is set according to MODE and COND (except there is no DMAX parameter for DL). If GRADE='E', then DL cannot have zero entries. Not referenced if GRADE = 'N' or 'R'. Changed on exit.
MODELMODEL is INTEGER This specifies how the diagonal array DL is to be computed, just as MODE specifies how D is to be computed. Not modified.
CONDLCONDL is REAL When MODEL is not zero, this specifies the condition number of the computed DL. Not modified.
DRDR is REAL array, dimension (N) If MODER=0, then on entry this array specifies the diagonal entries of a diagonal matrix used as described under GRADE above. If MODER is not zero, then DR will be set according to MODER and CONDR, analogous to the way D is set according to MODE and COND (except there is no DMAX parameter for DR). Not referenced if GRADE = 'N', 'L', 'H', 'S' or 'E'. Changed on exit.
MODERMODER is INTEGER This specifies how the diagonal array DR is to be computed, just as MODE specifies how D is to be computed. Not modified.
CONDRCONDR is REAL When MODER is not zero, this specifies the condition number of the computed DR. Not modified.
PIVTNGPIVTNG is CHARACTER*1 On entry specifies pivoting permutations as follows: 'N' or ' ' => none. 'L' => left or row pivoting (matrix must be nonsymmetric). 'R' => right or column pivoting (matrix must be nonsymmetric). 'B' or 'F' => both or full pivoting, i.e., on both sides. In this case, M must equal N If two calls to SLATMR both have full bandwidth (KL = M1 and KU = N1), and differ only in the PIVTNG and PACK parameters, then the matrices generated will differ only in the order of the rows and/or columns, and otherwise contain the same data. This consistency cannot be maintained with less than full bandwidth.
IPIVOTIPIVOT is INTEGER array, dimension (N or M) This array specifies the permutation used. After the basic matrix is generated, the rows, columns, or both are permuted. If, say, row pivoting is selected, SLATMR starts with the *last* row and interchanges the Mth and IPIVOT(M)th rows, then moves to the nexttolast row, interchanging the (M1)th and the IPIVOT(M1)th rows, and so on. In terms of "2cycles", the permutation is (1 IPIVOT(1)) (2 IPIVOT(2)) ... (M IPIVOT(M)) where the rightmost cycle is applied first. This is the *inverse* of the effect of pivoting in LINPACK. The idea is that factoring (with pivoting) an identity matrix which has been inversepivoted in this way should result in a pivot vector identical to IPIVOT. Not referenced if PIVTNG = 'N'. Not modified.
SPARSESPARSE is REAL On entry specifies the sparsity of the matrix if a sparse matrix is to be generated. SPARSE should lie between 0 and 1. To generate a sparse matrix, for each matrix entry a uniform ( 0, 1 ) random number x is generated and compared to SPARSE; if x is larger the matrix entry is unchanged and if x is smaller the entry is set to zero. Thus on the average a fraction SPARSE of the entries will be set to zero. Not modified.
KLKL is INTEGER On entry specifies the lower bandwidth of the matrix. For example, KL=0 implies upper triangular, KL=1 implies upper Hessenberg, and KL at least M1 implies the matrix is not banded. Must equal KU if matrix is symmetric. Not modified.
KUKU is INTEGER On entry specifies the upper bandwidth of the matrix. For example, KU=0 implies lower triangular, KU=1 implies lower Hessenberg, and KU at least N1 implies the matrix is not banded. Must equal KL if matrix is symmetric. Not modified.
ANORMANORM is REAL On entry specifies maximum entry of output matrix (output matrix will by multiplied by a constant so that its largest absolute entry equal ANORM) if ANORM is nonnegative. If ANORM is negative no scaling is done. Not modified.
PACKPACK is CHARACTER*1 On entry specifies packing of matrix as follows: 'N' => no packing 'U' => zero out all subdiagonal entries (if symmetric) 'L' => zero out all superdiagonal entries (if symmetric) 'C' => store the upper triangle columnwise (only if matrix symmetric or square upper triangular) 'R' => store the lower triangle columnwise (only if matrix symmetric or square lower triangular) (same as upper half rowwise if symmetric) 'B' => store the lower triangle in band storage scheme (only if matrix symmetric) 'Q' => store the upper triangle in band storage scheme (only if matrix symmetric) 'Z' => store the entire matrix in band storage scheme (pivoting can be provided for by using this option to store A in the trailing rows of the allocated storage) Using these options, the various LAPACK packed and banded storage schemes can be obtained: GB  use 'Z' PB, SB or TB  use 'B' or 'Q' PP, SP or TP  use 'C' or 'R' If two calls to SLATMR differ only in the PACK parameter, they will generate mathematically equivalent matrices. Not modified.
AA is REAL array, dimension (LDA,N) On exit A is the desired test matrix. Only those entries of A which are significant on output will be referenced (even if A is in packed or band storage format). The 'unoccupied corners' of A in band format will be zeroed out.
LDALDA is INTEGER on entry LDA specifies the first dimension of A as declared in the calling program. If PACK='N', 'U' or 'L', LDA must be at least max ( 1, M ). If PACK='C' or 'R', LDA must be at least 1. If PACK='B', or 'Q', LDA must be MIN ( KU+1, N ) If PACK='Z', LDA must be at least KUU+KLL+1, where KUU = MIN ( KU, N1 ) and KLL = MIN ( KL, N1 ) Not modified.
IWORKIWORK is INTEGER array, dimension ( N or M) Workspace. Not referenced if PIVTNG = 'N'. Changed on exit.
INFOINFO is INTEGER Error parameter on exit: 0 => normal return 1 => M negative or unequal to N and SYM='S' or 'H' 2 => N negative 3 => DIST illegal string 5 => SYM illegal string 7 => MODE not in range 6 to 6 8 => COND less than 1.0, and MODE neither 6, 0 nor 6 10 => MODE neither 6, 0 nor 6 and RSIGN illegal string 11 => GRADE illegal string, or GRADE='E' and M not equal to N, or GRADE='L', 'R', 'B' or 'E' and SYM = 'S' or 'H' 12 => GRADE = 'E' and DL contains zero 13 => MODEL not in range 6 to 6 and GRADE= 'L', 'B', 'H', 'S' or 'E' 14 => CONDL less than 1.0, GRADE='L', 'B', 'H', 'S' or 'E', and MODEL neither 6, 0 nor 6 16 => MODER not in range 6 to 6 and GRADE= 'R' or 'B' 17 => CONDR less than 1.0, GRADE='R' or 'B', and MODER neither 6, 0 nor 6 18 => PIVTNG illegal string, or PIVTNG='B' or 'F' and M not equal to N, or PIVTNG='L' or 'R' and SYM='S' or 'H' 19 => IPIVOT contains out of range number and PIVTNG not equal to 'N' 20 => KL negative 21 => KU negative, or SYM='S' or 'H' and KU not equal to KL 22 => SPARSE not in range 0. to 1. 24 => PACK illegal string, or PACK='U', 'L', 'B' or 'Q' and SYM='N', or PACK='C' and SYM='N' and either KL not equal to 0 or N not equal to M, or PACK='R' and SYM='N', and either KU not equal to 0 or N not equal to M 26 => LDA too small 1 => Error return from SLATM1 (computing D) 2 => Cannot scale diagonal to DMAX (max. entry is 0) 3 => Error return from SLATM1 (computing DL) 4 => Error return from SLATM1 (computing DR) 5 => ANORM is positive, but matrix constructed prior to attempting to scale it to have norm ANORM, is zero
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
subroutine slatms (integer M, integer N, character DIST, integer, dimension( 4 ) ISEED, character SYM, real, dimension( * ) D, integer MODE, real COND, real DMAX, integer KL, integer KU, character PACK, real, dimension( lda, * ) A, integer LDA, real, dimension( * ) WORK, integer INFO)
SLATMS
Purpose:

SLATMS generates random matrices with specified singular values (or symmetric/hermitian with specified eigenvalues) for testing LAPACK programs. SLATMS operates by applying the following sequence of operations: Set the diagonal to D, where D may be input or computed according to MODE, COND, DMAX, and SYM as described below. Generate a matrix with the appropriate band structure, by one of two methods: Method A: Generate a dense M x N matrix by multiplying D on the left and the right by random unitary matrices, then: Reduce the bandwidth according to KL and KU, using Householder transformations. Method B: Convert the bandwidth0 (i.e., diagonal) matrix to a bandwidth1 matrix using Givens rotations, "chasing" outofband elements back, much as in QR; then convert the bandwidth1 to a bandwidth2 matrix, etc. Note that for reasonably small bandwidths (relative to M and N) this requires less storage, as a dense matrix is not generated. Also, for symmetric matrices, only one triangle is generated. Method A is chosen if the bandwidth is a large fraction of the order of the matrix, and LDA is at least M (so a dense matrix can be stored.) Method B is chosen if the bandwidth is small (< 1/2 N for symmetric, < .3 N+M for nonsymmetric), or LDA is less than M and not less than the bandwidth. Pack the matrix if desired. Options specified by PACK are: no packing zero out upper half (if symmetric) zero out lower half (if symmetric) store the upper half columnwise (if symmetric or upper triangular) store the lower half columnwise (if symmetric or lower triangular) store the lower triangle in banded format (if symmetric or lower triangular) store the upper triangle in banded format (if symmetric or upper triangular) store the entire matrix in banded format If Method B is chosen, and band format is specified, then the matrix will be generated in the band format, so no repacking will be necessary.
Parameters:

M
M is INTEGER The number of rows of A. Not modified.
NN is INTEGER The number of columns of A. Not modified.
DISTDIST is CHARACTER*1 On entry, DIST specifies the type of distribution to be used to generate the random eigen/singular values. 'U' => UNIFORM( 0, 1 ) ( 'U' for uniform ) 'S' => UNIFORM( 1, 1 ) ( 'S' for symmetric ) 'N' => NORMAL( 0, 1 ) ( 'N' for normal ) Not modified.
ISEEDISEED is INTEGER array, dimension ( 4 ) On entry ISEED specifies the seed of the random number generator. They should lie between 0 and 4095 inclusive, and ISEED(4) should be odd. The random number generator uses a linear congruential sequence limited to small integers, and so should produce machine independent random numbers. The values of ISEED are changed on exit, and can be used in the next call to SLATMS to continue the same random number sequence. Changed on exit.
SYMSYM is CHARACTER*1 If SYM='S' or 'H', the generated matrix is symmetric, with eigenvalues specified by D, COND, MODE, and DMAX; they may be positive, negative, or zero. If SYM='P', the generated matrix is symmetric, with eigenvalues (= singular values) specified by D, COND, MODE, and DMAX; they will not be negative. If SYM='N', the generated matrix is nonsymmetric, with singular values specified by D, COND, MODE, and DMAX; they will not be negative. Not modified.
DD is REAL array, dimension ( MIN( M , N ) ) This array is used to specify the singular values or eigenvalues of A (see SYM, above.) If MODE=0, then D is assumed to contain the singular/eigenvalues, otherwise they will be computed according to MODE, COND, and DMAX, and placed in D. Modified if MODE is nonzero.
MODEMODE is INTEGER On entry this describes how the singular/eigenvalues are to be specified: MODE = 0 means use D as input MODE = 1 sets D(1)=1 and D(2:N)=1.0/COND MODE = 2 sets D(1:N1)=1 and D(N)=1.0/COND MODE = 3 sets D(I)=COND**((I1)/(N1)) MODE = 4 sets D(i)=1  (i1)/(N1)*(1  1/COND) MODE = 5 sets D to random numbers in the range ( 1/COND , 1 ) such that their logarithms are uniformly distributed. MODE = 6 set D to random numbers from same distribution as the rest of the matrix. MODE < 0 has the same meaning as ABS(MODE), except that the order of the elements of D is reversed. Thus if MODE is positive, D has entries ranging from 1 to 1/COND, if negative, from 1/COND to 1, If SYM='S' or 'H', and MODE is neither 0, 6, nor 6, then the elements of D will also be multiplied by a random sign (i.e., +1 or 1.) Not modified.
CONDCOND is REAL On entry, this is used as described under MODE above. If used, it must be >= 1. Not modified.
DMAXDMAX is REAL If MODE is neither 6, 0 nor 6, the contents of D, as computed according to MODE and COND, will be scaled by DMAX / max(abs(D(i))); thus, the maximum absolute eigen or singular value (which is to say the norm) will be abs(DMAX). Note that DMAX need not be positive: if DMAX is negative (or zero), D will be scaled by a negative number (or zero). Not modified.
KLKL is INTEGER This specifies the lower bandwidth of the matrix. For example, KL=0 implies upper triangular, KL=1 implies upper Hessenberg, and KL being at least M1 means that the matrix has full lower bandwidth. KL must equal KU if the matrix is symmetric. Not modified.
KUKU is INTEGER This specifies the upper bandwidth of the matrix. For example, KU=0 implies lower triangular, KU=1 implies lower Hessenberg, and KU being at least N1 means that the matrix has full upper bandwidth. KL must equal KU if the matrix is symmetric. Not modified.
PACKPACK is CHARACTER*1 This specifies packing of matrix as follows: 'N' => no packing 'U' => zero out all subdiagonal entries (if symmetric) 'L' => zero out all superdiagonal entries (if symmetric) 'C' => store the upper triangle columnwise (only if the matrix is symmetric or upper triangular) 'R' => store the lower triangle columnwise (only if the matrix is symmetric or lower triangular) 'B' => store the lower triangle in band storage scheme (only if matrix symmetric or lower triangular) 'Q' => store the upper triangle in band storage scheme (only if matrix symmetric or upper triangular) 'Z' => store the entire matrix in band storage scheme (pivoting can be provided for by using this option to store A in the trailing rows of the allocated storage) Using these options, the various LAPACK packed and banded storage schemes can be obtained: GB  use 'Z' PB, SB or TB  use 'B' or 'Q' PP, SP or TP  use 'C' or 'R' If two calls to SLATMS differ only in the PACK parameter, they will generate mathematically equivalent matrices. Not modified.
AA is REAL array, dimension ( LDA, N ) On exit A is the desired test matrix. A is first generated in full (unpacked) form, and then packed, if so specified by PACK. Thus, the first M elements of the first N columns will always be modified. If PACK specifies a packed or banded storage scheme, all LDA elements of the first N columns will be modified; the elements of the array which do not correspond to elements of the generated matrix are set to zero. Modified.
LDALDA is INTEGER LDA specifies the first dimension of A as declared in the calling program. If PACK='N', 'U', 'L', 'C', or 'R', then LDA must be at least M. If PACK='B' or 'Q', then LDA must be at least MIN( KL, M1) (which is equal to MIN(KU,N1)). If PACK='Z', LDA must be large enough to hold the packed array: MIN( KU, N1) + MIN( KL, M1) + 1. Not modified.
WORKWORK is REAL array, dimension ( 3*MAX( N , M ) ) Workspace. Modified.
INFOINFO is INTEGER Error code. On exit, INFO will be set to one of the following values: 0 => normal return 1 => M negative or unequal to N and SYM='S', 'H', or 'P' 2 => N negative 3 => DIST illegal string 5 => SYM illegal string 7 => MODE not in range 6 to 6 8 => COND less than 1.0, and MODE neither 6, 0 nor 6 10 => KL negative 11 => KU negative, or SYM='S' or 'H' and KU not equal to KL 12 => PACK illegal string, or PACK='U' or 'L', and SYM='N'; or PACK='C' or 'Q' and SYM='N' and KL is not zero; or PACK='R' or 'B' and SYM='N' and KU is not zero; or PACK='U', 'L', 'C', 'R', 'B', or 'Q', and M is not N. 14 => LDA is less than M, or PACK='Z' and LDA is less than MIN(KU,N1) + MIN(KL,M1) + 1. 1 => Error return from SLATM1 2 => Cannot scale to DMAX (max. sing. value is 0) 3 => Error return from SLAGGE or SLAGSY
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
subroutine slatmt (integer M, integer N, character DIST, integer, dimension( 4 ) ISEED, character SYM, real, dimension( * ) D, integer MODE, real COND, real DMAX, integer RANK, integer KL, integer KU, character PACK, real, dimension( lda, * ) A, integer LDA, real, dimension( * ) WORK, integer INFO)
SLATMT
Purpose:

SLATMT generates random matrices with specified singular values (or symmetric/hermitian with specified eigenvalues) for testing LAPACK programs. SLATMT operates by applying the following sequence of operations: Set the diagonal to D, where D may be input or computed according to MODE, COND, DMAX, and SYM as described below. Generate a matrix with the appropriate band structure, by one of two methods: Method A: Generate a dense M x N matrix by multiplying D on the left and the right by random unitary matrices, then: Reduce the bandwidth according to KL and KU, using Householder transformations. Method B: Convert the bandwidth0 (i.e., diagonal) matrix to a bandwidth1 matrix using Givens rotations, "chasing" outofband elements back, much as in QR; then convert the bandwidth1 to a bandwidth2 matrix, etc. Note that for reasonably small bandwidths (relative to M and N) this requires less storage, as a dense matrix is not generated. Also, for symmetric matrices, only one triangle is generated. Method A is chosen if the bandwidth is a large fraction of the order of the matrix, and LDA is at least M (so a dense matrix can be stored.) Method B is chosen if the bandwidth is small (< 1/2 N for symmetric, < .3 N+M for nonsymmetric), or LDA is less than M and not less than the bandwidth. Pack the matrix if desired. Options specified by PACK are: no packing zero out upper half (if symmetric) zero out lower half (if symmetric) store the upper half columnwise (if symmetric or upper triangular) store the lower half columnwise (if symmetric or lower triangular) store the lower triangle in banded format (if symmetric or lower triangular) store the upper triangle in banded format (if symmetric or upper triangular) store the entire matrix in banded format If Method B is chosen, and band format is specified, then the matrix will be generated in the band format, so no repacking will be necessary.
Parameters:

M
M is INTEGER The number of rows of A. Not modified.
NN is INTEGER The number of columns of A. Not modified.
DISTDIST is CHARACTER*1 On entry, DIST specifies the type of distribution to be used to generate the random eigen/singular values. 'U' => UNIFORM( 0, 1 ) ( 'U' for uniform ) 'S' => UNIFORM( 1, 1 ) ( 'S' for symmetric ) 'N' => NORMAL( 0, 1 ) ( 'N' for normal ) Not modified.
ISEEDISEED is INTEGER array, dimension ( 4 ) On entry ISEED specifies the seed of the random number generator. They should lie between 0 and 4095 inclusive, and ISEED(4) should be odd. The random number generator uses a linear congruential sequence limited to small integers, and so should produce machine independent random numbers. The values of ISEED are changed on exit, and can be used in the next call to SLATMT to continue the same random number sequence. Changed on exit.
SYMSYM is CHARACTER*1 If SYM='S' or 'H', the generated matrix is symmetric, with eigenvalues specified by D, COND, MODE, and DMAX; they may be positive, negative, or zero. If SYM='P', the generated matrix is symmetric, with eigenvalues (= singular values) specified by D, COND, MODE, and DMAX; they will not be negative. If SYM='N', the generated matrix is nonsymmetric, with singular values specified by D, COND, MODE, and DMAX; they will not be negative. Not modified.
DD is REAL array, dimension ( MIN( M , N ) ) This array is used to specify the singular values or eigenvalues of A (see SYM, above.) If MODE=0, then D is assumed to contain the singular/eigenvalues, otherwise they will be computed according to MODE, COND, and DMAX, and placed in D. Modified if MODE is nonzero.
MODEMODE is INTEGER On entry this describes how the singular/eigenvalues are to be specified: MODE = 0 means use D as input MODE = 1 sets D(1)=1 and D(2:RANK)=1.0/COND MODE = 2 sets D(1:RANK1)=1 and D(RANK)=1.0/COND MODE = 3 sets D(I)=COND**((I1)/(RANK1)) MODE = 4 sets D(i)=1  (i1)/(N1)*(1  1/COND) MODE = 5 sets D to random numbers in the range ( 1/COND , 1 ) such that their logarithms are uniformly distributed. MODE = 6 set D to random numbers from same distribution as the rest of the matrix. MODE < 0 has the same meaning as ABS(MODE), except that the order of the elements of D is reversed. Thus if MODE is positive, D has entries ranging from 1 to 1/COND, if negative, from 1/COND to 1, If SYM='S' or 'H', and MODE is neither 0, 6, nor 6, then the elements of D will also be multiplied by a random sign (i.e., +1 or 1.) Not modified.
CONDCOND is REAL On entry, this is used as described under MODE above. If used, it must be >= 1. Not modified.
DMAXDMAX is REAL If MODE is neither 6, 0 nor 6, the contents of D, as computed according to MODE and COND, will be scaled by DMAX / max(abs(D(i))); thus, the maximum absolute eigen or singular value (which is to say the norm) will be abs(DMAX). Note that DMAX need not be positive: if DMAX is negative (or zero), D will be scaled by a negative number (or zero). Not modified.
RANKRANK is INTEGER The rank of matrix to be generated for modes 1,2,3 only. D( RANK+1:N ) = 0. Not modified.
KLKL is INTEGER This specifies the lower bandwidth of the matrix. For example, KL=0 implies upper triangular, KL=1 implies upper Hessenberg, and KL being at least M1 means that the matrix has full lower bandwidth. KL must equal KU if the matrix is symmetric. Not modified.
KUKU is INTEGER This specifies the upper bandwidth of the matrix. For example, KU=0 implies lower triangular, KU=1 implies lower Hessenberg, and KU being at least N1 means that the matrix has full upper bandwidth. KL must equal KU if the matrix is symmetric. Not modified.
PACKPACK is CHARACTER*1 This specifies packing of matrix as follows: 'N' => no packing 'U' => zero out all subdiagonal entries (if symmetric) 'L' => zero out all superdiagonal entries (if symmetric) 'C' => store the upper triangle columnwise (only if the matrix is symmetric or upper triangular) 'R' => store the lower triangle columnwise (only if the matrix is symmetric or lower triangular) 'B' => store the lower triangle in band storage scheme (only if matrix symmetric or lower triangular) 'Q' => store the upper triangle in band storage scheme (only if matrix symmetric or upper triangular) 'Z' => store the entire matrix in band storage scheme (pivoting can be provided for by using this option to store A in the trailing rows of the allocated storage) Using these options, the various LAPACK packed and banded storage schemes can be obtained: GB  use 'Z' PB, SB or TB  use 'B' or 'Q' PP, SP or TP  use 'C' or 'R' If two calls to SLATMT differ only in the PACK parameter, they will generate mathematically equivalent matrices. Not modified.
AA is REAL array, dimension ( LDA, N ) On exit A is the desired test matrix. A is first generated in full (unpacked) form, and then packed, if so specified by PACK. Thus, the first M elements of the first N columns will always be modified. If PACK specifies a packed or banded storage scheme, all LDA elements of the first N columns will be modified; the elements of the array which do not correspond to elements of the generated matrix are set to zero. Modified.
LDALDA is INTEGER LDA specifies the first dimension of A as declared in the calling program. If PACK='N', 'U', 'L', 'C', or 'R', then LDA must be at least M. If PACK='B' or 'Q', then LDA must be at least MIN( KL, M1) (which is equal to MIN(KU,N1)). If PACK='Z', LDA must be large enough to hold the packed array: MIN( KU, N1) + MIN( KL, M1) + 1. Not modified.
WORKWORK is REAL array, dimension ( 3*MAX( N , M ) ) Workspace. Modified.
INFOINFO is INTEGER Error code. On exit, INFO will be set to one of the following values: 0 => normal return 1 => M negative or unequal to N and SYM='S', 'H', or 'P' 2 => N negative 3 => DIST illegal string 5 => SYM illegal string 7 => MODE not in range 6 to 6 8 => COND less than 1.0, and MODE neither 6, 0 nor 6 10 => KL negative 11 => KU negative, or SYM='S' or 'H' and KU not equal to KL 12 => PACK illegal string, or PACK='U' or 'L', and SYM='N'; or PACK='C' or 'Q' and SYM='N' and KL is not zero; or PACK='R' or 'B' and SYM='N' and KU is not zero; or PACK='U', 'L', 'C', 'R', 'B', or 'Q', and M is not N. 14 => LDA is less than M, or PACK='Z' and LDA is less than MIN(KU,N1) + MIN(KL,M1) + 1. 1 => Error return from SLATM7 2 => Cannot scale to DMAX (max. sing. value is 0) 3 => Error return from SLAGGE or SLAGSY
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
Author
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