Actual source code: numsrt.c

  1: /* numsrt.f -- translated by f2c (version of 25 March 1992  12:58:56). */

  3: #include <../src/mat/color/impls/minpack/color.h>

  5: PetscErrorCode MINPACKnumsrt(PetscInt *n, PetscInt *nmax, PetscInt *num, PetscInt *mode, PetscInt *idex, PetscInt *last, PetscInt *next)
  6: {
  7:   /* System generated locals */
  8:   PetscInt i__1, i__2;

 10:   /* Local variables */
 11:   PetscInt jinc, i, j, k, l, jl, ju;

 13:   /*     Given a sequence of integers, this subroutine groups */
 14:   /*     together those indices with the same sequence value */
 15:   /*     and, optionally, sorts the sequence into either */
 16:   /*     ascending or descending order. */
 17:   /*     The sequence of integers is defined by the array num, */
 18:   /*     and it is assumed that the integers are each from the set */
 19:   /*     0,1,...,nmax. On output the indices k such that num(k) = l */
 20:   /*     for any l = 0,1,...,nmax can be obtained from the arrays */
 21:   /*     last and next as follows. */
 22:   /*           k = last(l) */
 23:   /*           while (k .ne. 0) k = next(k) */
 24:   /*     Optionally, the subroutine produces an array index so that */
 25:   /*     the sequence num(index(i)), i = 1,2,...,n is sorted. */
 26:   /*     The subroutine statement is */
 27:   /*       subroutine numsrt(n,nmax,num,mode,index,last,next) */
 28:   /*     where */
 29:   /*       n is a positive integer input variable. */
 30:   /*       nmax is a positive integer input variable. */
 31:   /*       num is an input array of length n which contains the */
 32:   /*         sequence of integers to be grouped and sorted. It */
 33:   /*         is assumed that the integers are each from the set */
 34:   /*         0,1,...,nmax. */
 35:   /*       mode is an integer input variable. The sequence num is */
 36:   /*         sorted in ascending order if mode is positive and in */
 37:   /*         descending order if mode is negative. If mode is 0, */
 38:   /*         no sorting is done. */
 39:   /*       index is an integer output array of length n set so */
 40:   /*         that the sequence */
 41:   /*               num(index(i)), i = 1,2,...,n */
 42:   /*         is sorted according to the setting of mode. If mode */
 43:   /*         is 0, index is not referenced. */
 44:   /*       last is an integer output array of length nmax + 1. The */
 45:   /*         index of num for the last occurrence of l is last(l) */
 46:   /*         for any l = 0,1,...,nmax unless last(l) = 0. In */
 47:   /*         this case l does not appear in num. */
 48:   /*       next is an integer output array of length n. If */
 49:   /*         num(k) = l, then the index of num for the previous */
 50:   /*         occurrence of l is next(k) for any l = 0,1,...,nmax */
 51:   /*         unless next(k) = 0. In this case there is no previous */
 52:   /*         occurrence of l in num. */
 53:   /*     Argonne National Laboratory. MINPACK Project. July 1983. */
 54:   /*     Thomas F. Coleman, Burton S. Garbow, Jorge J. More' */

 56:   /* Parameter adjustments */
 57:   PetscFunctionBegin;
 58:   --next;
 59:   --idex;
 60:   --num;

 62:   i__1 = *nmax;
 63:   for (i = 0; i <= i__1; ++i) last[i] = 0;

 65:   i__1 = *n;
 66:   for (k = 1; k <= i__1; ++k) {
 67:     l       = num[k];
 68:     next[k] = last[l];
 69:     last[l] = k;
 70:   }
 71:   if (!*mode) PetscFunctionReturn(PETSC_SUCCESS);

 73:   /*     Store the pointers to the sorted array in index. */

 75:   i = 1;
 76:   if (*mode > 0) {
 77:     jl   = 0;
 78:     ju   = *nmax;
 79:     jinc = 1;
 80:   } else {
 81:     jl   = *nmax;
 82:     ju   = 0;
 83:     jinc = -1;
 84:   }
 85:   i__1 = ju;
 86:   i__2 = jinc;
 87:   for (j = jl; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
 88:     k = last[j];
 89:   L30:
 90:     if (!k) goto L40;
 91:     idex[i] = k;
 92:     ++i;
 93:     k = next[k];
 94:     goto L30;
 95:   L40:;
 96:   }
 97:   PetscFunctionReturn(PETSC_SUCCESS);
 98: }