72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
#include "f2c.h"
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integer icamax_(integer *n, complex *cx, integer *incx)
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{
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/* System generated locals */
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integer ret_val, i__1, i__2;
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real r__1, r__2;
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/* Builtin functions */
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double r_imag(complex *);
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/* Local variables */
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static real smax;
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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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Function Body */
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#define CX(I) cx[(I)-1]
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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 = (r__1 = CX(1).r, dabs(r__1)) + (r__2 = r_imag(&CX(1)), dabs(r__2));
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ix += *incx;
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i__1 = *n;
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for (i = 2; i <= *n; ++i) {
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i__2 = ix;
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if ((r__1 = CX(ix).r, dabs(r__1)) + (r__2 = r_imag(&CX(ix)), dabs(
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r__2)) <= smax) {
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goto L5;
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}
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ret_val = i;
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i__2 = ix;
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smax = (r__1 = CX(ix).r, dabs(r__1)) + (r__2 = r_imag(&CX(ix)),
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dabs(r__2));
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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 = (r__1 = CX(1).r, dabs(r__1)) + (r__2 = r_imag(&CX(1)), dabs(r__2));
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i__1 = *n;
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for (i = 2; i <= *n; ++i) {
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i__2 = i;
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if ((r__1 = CX(i).r, dabs(r__1)) + (r__2 = r_imag(&CX(i)), dabs(
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r__2)) <= smax) {
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goto L30;
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}
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ret_val = i;
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i__2 = i;
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smax = (r__1 = CX(i).r, dabs(r__1)) + (r__2 = r_imag(&CX(i)), dabs(
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r__2));
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L30:
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;
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}
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return ret_val;
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} /* icamax_ */
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