| 1 | struct complex { float real, imag; }; |
| 2 | |
| 3 | c_div(c, a, b) |
| 4 | struct complex *a, *b, *c; |
| 5 | { |
| 6 | double ratio, den; |
| 7 | double abr, abi; |
| 8 | |
| 9 | if( (abr = b->real) < 0.) |
| 10 | abr = - abr; |
| 11 | if( (abi = b->imag) < 0.) |
| 12 | abi = - abi; |
| 13 | if( abr <= abi ) |
| 14 | { |
| 15 | if(abi == 0) |
| 16 | abort(); /* fatal("complex division by zero"); */ |
| 17 | ratio = b->real / b->imag ; |
| 18 | den = b->imag * (1 + ratio*ratio); |
| 19 | c->real = (a->real*ratio + a->imag) / den; |
| 20 | c->imag = (a->imag*ratio - a->real) / den; |
| 21 | } |
| 22 | |
| 23 | else |
| 24 | { |
| 25 | ratio = b->imag / b->real ; |
| 26 | den = b->real * (1 + ratio*ratio); |
| 27 | c->real = (a->real + a->imag*ratio) / den; |
| 28 | c->imag = (a->imag - a->real*ratio) / den; |
| 29 | } |
| 30 | |
| 31 | } |