DLAMRG (3lapack)

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 DLAMRG( N1, N2, A, DTRD1, DTRD2, INDEX )

      INTEGER        DTRD1, DTRD2, N1, N2

      INTEGER        INDEX( * )

      DOUBLE         PRECISION A( * )

PURPOSE

  DLAMRG 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) DOUBLE PRECISION 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.

  DTRD1  (input) INTEGER
         DTRD2  (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 (DTRDx = 1) or descending (DTRDx
         = -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.