/* -- translated by f2c (version 19940927).
You must link the resulting object file with the libraries:
-lf2c -lm (in that order)
*/
#include "f2c.h"
doublereal dznrm2_(integer *n, doublecomplex *x, integer *incx)
{
/* System generated locals */
integer i__1, i__2, i__3;
doublereal ret_val, d__1;
/* Builtin functions */
double d_imag(doublecomplex *), sqrt(doublereal);
/* Local variables */
static doublereal temp, norm, scale;
static integer ix;
static doublereal ssq;
/* DZNRM2 returns the euclidean norm of a vector via the function
name, so that
DZNRM2 := sqrt( conjg( x' )*x )
-- This version written on 25-October-1982.
Modified on 14-October-1993 to inline the call to ZLASSQ.
Sven Hammarling, Nag Ltd.
Parameter adjustments
Function Body */
#define X(I) x[(I)-1]
if (*n < 1 || *incx < 1) {
norm = 0.;
} else {
scale = 0.;
ssq = 1.;
/* The following loop is equivalent to this call to the LAPACK
auxiliary routine:
CALL ZLASSQ( N, X, INCX, SCALE, SSQ ) */
i__1 = (*n - 1) * *incx + 1;
i__2 = *incx;
for (ix = 1; *incx < 0 ? ix >= (*n-1)**incx+1 : ix <= (*n-1)**incx+1; ix += *incx) {
i__3 = ix;
if (X(ix).r != 0.) {
i__3 = ix;
temp = (d__1 = X(ix).r, abs(d__1));
if (scale < temp) {
/* Computing 2nd power */
d__1 = scale / temp;
ssq = ssq * (d__1 * d__1) + 1.;
scale = temp;
} else {
/* Computing 2nd power */
d__1 = temp / scale;
ssq += d__1 * d__1;
}
}
if (d_imag(&X(ix)) != 0.) {
temp = (d__1 = d_imag(&X(ix)), abs(d__1));
if (scale < temp) {
/* Computing 2nd power */
d__1 = scale / temp;
ssq = ssq * (d__1 * d__1) + 1.;
scale = temp;
} else {
/* Computing 2nd power */
d__1 = temp / scale;
ssq += d__1 * d__1;
}
}
/* L10: */
}
norm = scale * sqrt(ssq);
}
ret_val = norm;
return ret_val;
/* End of DZNRM2. */
} /* dznrm2_ */