opencv/3rdparty/lapack/slamrg.c

119 lines
2.8 KiB
C

#include "clapack.h"
/* Subroutine */ int slamrg_(integer *n1, integer *n2, real *a, integer *
strd1, integer *strd2, integer *index)
{
/* System generated locals */
integer i__1;
/* Local variables */
integer i__, ind1, ind2, n1sv, n2sv;
/* -- LAPACK routine (version 3.1) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* 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. */
/* ===================================================================== */
/* .. Local Scalars .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
--index;
--a;
/* Function Body */
n1sv = *n1;
n2sv = *n2;
if (*strd1 > 0) {
ind1 = 1;
} else {
ind1 = *n1;
}
if (*strd2 > 0) {
ind2 = *n1 + 1;
} else {
ind2 = *n1 + *n2;
}
i__ = 1;
/* while ( (N1SV > 0) & (N2SV > 0) ) */
L10:
if (n1sv > 0 && n2sv > 0) {
if (a[ind1] <= a[ind2]) {
index[i__] = ind1;
++i__;
ind1 += *strd1;
--n1sv;
} else {
index[i__] = ind2;
++i__;
ind2 += *strd2;
--n2sv;
}
goto L10;
}
/* end while */
if (n1sv == 0) {
i__1 = n2sv;
for (n1sv = 1; n1sv <= i__1; ++n1sv) {
index[i__] = ind2;
++i__;
ind2 += *strd2;
/* L20: */
}
} else {
/* N2SV .EQ. 0 */
i__1 = n1sv;
for (n2sv = 1; n2sv <= i__1; ++n2sv) {
index[i__] = ind1;
++i__;
ind1 += *strd1;
/* L30: */
}
}
return 0;
/* End of SLAMRG */
} /* slamrg_ */