Go to the documentation of this file.00001 #include "f2c.h"
00002
00003 #ifdef KR_headers
00004 double sqrt(), f__cabs();
00005 VOID z_sqrt(r, z) doublecomplex *r, *z;
00006 #else
00007 #undef abs
00008 #include "math.h"
00009 #ifdef __cplusplus
00010 extern "C" {
00011 #endif
00012 extern double f__cabs(double, double);
00013 void z_sqrt(doublecomplex *r, doublecomplex *z)
00014 #endif
00015 {
00016 double mag, zi = z->i, zr = z->r;
00017
00018 if( (mag = f__cabs(zr, zi)) == 0.)
00019 r->r = r->i = 0.;
00020 else if(zr > 0)
00021 {
00022 r->r = sqrt(0.5 * (mag + zr) );
00023 r->i = zi / r->r / 2;
00024 }
00025 else
00026 {
00027 r->i = sqrt(0.5 * (mag - zr) );
00028 if(zi < 0)
00029 r->i = - r->i;
00030 r->r = zi / r->i / 2;
00031 }
00032 }
00033 #ifdef __cplusplus
00034 }
00035 #endif