SLAMRG(3) will create a permutation list which will merge the elements of A (which is composed of two independently sorted sets) into a single set which is sorted in ascending order

SYNOPSIS

SUBROUTINE SLAMRG(
N1, N2, A, STRD1, STRD2, INDEX )

    
INTEGER N1, N2, STRD1, STRD2

    
INTEGER INDEX( * )

    
REAL A( * )

PURPOSE

SLAMRG will create a permutation list which will merge the elements of A (which is composed of two independently sorted sets) into a single set which is sorted in ascending order.

ARGUMENTS

N1 (input) INTEGER
N2 (input) INTEGER These arguements contain the respective lengths of the two sorted lists to be merged.
A (input) REAL array, dimension (N1+N2)
The first N1 elements of A contain a list of numbers which are sorted in either ascending or descending order. Likewise for the final N2 elements.
STRD1 (input) INTEGER
STRD2 (input) INTEGER These are the strides to be taken through the array A. Allowable strides are 1 and -1. They indicate whether a subset of A is sorted in ascending (STRDx = 1) or descending (STRDx = -1) order.
INDEX (output) INTEGER array, dimension (N1+N2)
On exit this array will contain a permutation such that if B( I ) = A( INDEX( I ) ) for I=1,N1+N2, then B will be sorted in ascending order.