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Annotation of 40BSD/lib/libF77/z_sqrt.c, revision 1.1.1.1

1.1       root        1: #include "complex"
                      2: 
                      3: z_sqrt(r, z)
                      4: dcomplex *r, *z;
                      5: {
                      6: double mag, sqrt(), cabs();
                      7: 
                      8: if( (mag = cabs(z->dreal, z->dimag)) == 0.)
                      9:        r->dreal = r->dimag = 0.;
                     10: else if(z->dreal > 0)
                     11:        {
                     12:        r->dreal = sqrt(0.5 * (mag + z->dreal) );
                     13:        r->dimag = z->dimag / r->dreal / 2;
                     14:        }
                     15: else
                     16:        {
                     17:        r->dimag = sqrt(0.5 * (mag - z->dreal) );
                     18:        if(z->dimag < 0)
                     19:                z->dimag = - z->dimag;
                     20:        r->dreal = z->dimag / r->dimag / 2;
                     21:        }
                     22: }

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