mirror of
https://github.com/Cantera/cantera.git
synced 2025-02-25 18:55:29 -06:00
69 lines
1.6 KiB
C
69 lines
1.6 KiB
C
#include "blaswrap.h"
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
#include "f2c.h"
|
|
|
|
doublereal dnrm2_(integer *n, doublereal *x, integer *incx)
|
|
{
|
|
/* The following loop is equivalent to this call to the LAPACK
|
|
auxiliary routine:
|
|
CALL DLASSQ( N, X, INCX, SCALE, SSQ ) */
|
|
/* System generated locals */
|
|
integer i__1, i__2;
|
|
doublereal ret_val, d__1;
|
|
/* Builtin functions */
|
|
double sqrt(doublereal);
|
|
/* Local variables */
|
|
static doublereal norm, scale, absxi;
|
|
static integer ix;
|
|
static doublereal ssq;
|
|
/* DNRM2 returns the euclidean norm of a vector via the function
|
|
name, so that
|
|
DNRM2 := sqrt( x'*x )
|
|
-- This version written on 25-October-1982.
|
|
Modified on 14-October-1993 to inline the call to DLASSQ.
|
|
Sven Hammarling, Nag Ltd.
|
|
Parameter adjustments */
|
|
--x;
|
|
/* Function Body */
|
|
if (*n < 1 || *incx < 1) {
|
|
norm = 0.;
|
|
} else if (*n == 1) {
|
|
norm = abs(x[1]);
|
|
} else {
|
|
scale = 0.;
|
|
ssq = 1.;
|
|
|
|
|
|
i__1 = (*n - 1) * *incx + 1;
|
|
i__2 = *incx;
|
|
for (ix = 1; i__2 < 0 ? ix >= i__1 : ix <= i__1; ix += i__2) {
|
|
if (x[ix] != 0.) {
|
|
absxi = (d__1 = x[ix], abs(d__1));
|
|
if (scale < absxi) {
|
|
/* Computing 2nd power */
|
|
d__1 = scale / absxi;
|
|
ssq = ssq * (d__1 * d__1) + 1.;
|
|
scale = absxi;
|
|
} else {
|
|
/* Computing 2nd power */
|
|
d__1 = absxi / scale;
|
|
ssq += d__1 * d__1;
|
|
}
|
|
}
|
|
/* L10: */
|
|
}
|
|
norm = scale * sqrt(ssq);
|
|
}
|
|
|
|
ret_val = norm;
|
|
return ret_val;
|
|
|
|
/* End of DNRM2. */
|
|
|
|
} /* dnrm2_ */
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|