SYNOPSIS
 SUBROUTINE DLASRT(
 ID, N, D, INFO )
 CHARACTER ID
 INTEGER INFO, N
 DOUBLE PRECISION D( * )
PURPOSE
Sort the numbers in D in increasing order (if ID = 'I') or in decreasing order (if ID = 'D' ). Use Quick Sort, reverting to Insertion sort on arrays ofsize <= 20. Dimension of STACK limits N to about 2**32.
ARGUMENTS
 ID (input) CHARACTER*1

= 'I': sort D in increasing order;
= 'D': sort D in decreasing order.  N (input) INTEGER
 The length of the array D.
 D (input/output) DOUBLE PRECISION array, dimension (N)
 On entry, the array to be sorted. On exit, D has been sorted into increasing order (D(1) <= ... <= D(N) ) or into decreasing order (D(1) >= ... >= D(N) ), depending on ID.
 INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value