LASRT - 5.2 English - 68552

LASRT sorts numbers in increasing or decreasing order.

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.

Parameters:

• ID – [in]

  ID is CHARACTER*1

  = ‘I’: sort D in increasing order;

  = ‘D’: sort D in decreasing order.

• N – [in]

  N is INTEGER

  The length of the array D.

• D – [inout]

  D is REAL 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 – [out]

  INFO is INTEGER

  = 0: successful exit

  < 0: if INFO = -i, the i-th argument had an illegal value