94 lines
1.9 KiB
C
94 lines
1.9 KiB
C
/* isamax.f -- translated by f2c (version 20061008).
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You must link the resulting object file with libf2c:
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on Microsoft Windows system, link with libf2c.lib;
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on Linux or Unix systems, link with .../path/to/libf2c.a -lm
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or, if you install libf2c.a in a standard place, with -lf2c -lm
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-- in that order, at the end of the command line, as in
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cc *.o -lf2c -lm
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Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
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http://www.netlib.org/f2c/libf2c.zip
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*/
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#include "clapack.h"
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integer isamax_(integer *n, real *sx, integer *incx)
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{
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/* System generated locals */
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integer ret_val, i__1;
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real r__1;
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/* Local variables */
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integer i__, ix;
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real smax;
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/* .. Scalar Arguments .. */
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/* .. */
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/* .. Array Arguments .. */
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/* .. */
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/* Purpose */
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/* ======= */
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/* finds the index of element having max. absolute value. */
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/* jack dongarra, linpack, 3/11/78. */
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/* modified 3/93 to return if incx .le. 0. */
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/* modified 12/3/93, array(1) declarations changed to array(*) */
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/* .. Local Scalars .. */
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/* .. */
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/* .. Intrinsic Functions .. */
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/* .. */
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/* Parameter adjustments */
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--sx;
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/* Function Body */
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ret_val = 0;
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if (*n < 1 || *incx <= 0) {
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return ret_val;
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}
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ret_val = 1;
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if (*n == 1) {
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return ret_val;
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}
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if (*incx == 1) {
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goto L20;
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}
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/* code for increment not equal to 1 */
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ix = 1;
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smax = dabs(sx[1]);
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ix += *incx;
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i__1 = *n;
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for (i__ = 2; i__ <= i__1; ++i__) {
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if ((r__1 = sx[ix], dabs(r__1)) <= smax) {
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goto L5;
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}
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ret_val = i__;
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smax = (r__1 = sx[ix], dabs(r__1));
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L5:
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ix += *incx;
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/* L10: */
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}
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return ret_val;
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/* code for increment equal to 1 */
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L20:
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smax = dabs(sx[1]);
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i__1 = *n;
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for (i__ = 2; i__ <= i__1; ++i__) {
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if ((r__1 = sx[i__], dabs(r__1)) <= smax) {
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goto L30;
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}
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ret_val = i__;
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smax = (r__1 = sx[i__], dabs(r__1));
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L30:
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;
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}
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return ret_val;
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} /* isamax_ */
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