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62 lines
1.3 KiB
62 lines
1.3 KiB
#include "blaswrap.h"
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#include "f2c.h"
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integer idamax_(integer *n, doublereal *dx, 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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doublereal d__1;
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/* Local variables */
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static doublereal dmax__;
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static integer i__, ix;
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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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Parameter adjustments */
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--dx;
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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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dmax__ = abs(dx[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 ((d__1 = dx[ix], abs(d__1)) <= dmax__) {
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goto L5;
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}
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ret_val = i__;
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dmax__ = (d__1 = dx[ix], abs(d__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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dmax__ = abs(dx[1]);
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i__1 = *n;
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for (i__ = 2; i__ <= i__1; ++i__) {
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if ((d__1 = dx[i__], abs(d__1)) <= dmax__) {
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goto L30;
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}
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ret_val = i__;
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dmax__ = (d__1 = dx[i__], abs(d__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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} /* idamax_ */
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