#include "blaswrap.h" #include "f2c.h" doublereal dznrm2_(integer *n, doublecomplex *x, integer *incx) { /* The following loop is equivalent to this call to the LAPACK auxiliary routine: CALL ZLASSQ( N, X, INCX, SCALE, SSQ ) */ /* 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 integer ix; static doublereal ssq, temp, norm, scale; /* Purpose ======= 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 */ --x; /* Function Body */ if (*n < 1 || *incx < 1) { norm = 0.; } 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) { i__3 = ix; if (x[i__3].r != 0.) { i__3 = ix; temp = (d__1 = x[i__3].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_ */