DLASRT (3lapack)

the numbers in D in increasing order (if ID = 'I') or in decreasing order (if ID = 'D' )

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 of
  size <= 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 i-th argument had an illegal value