| /** |
| * This file has no copyright assigned and is placed in the Public Domain. |
| * This file is part of the w64 mingw-runtime package. |
| * No warranty is given; refer to the file DISCLAIMER.PD within this package. |
| */ |
| /* |
| Contributed by Danny Smith |
| 2003-10-20 |
| */ |
| |
| |
| #include <math.h> |
| #include <complex.h> |
| #include <errno.h> |
| |
| /* |
| ctanh (x + I * y) = (sinh (2 * x) + sin (2 * y) * I ) |
| / (cosh (2 * x) + cos (2 * y)) . |
| */ |
| |
| double complex |
| ctanh (double complex Z) |
| { |
| double complex Res; |
| double two_R = 2.0 * __real__ Z; |
| double two_I = 2.0 * __imag__ Z; |
| double denom = cosh (two_R) + cos (two_I); |
| |
| if (denom == 0.0) |
| { |
| errno = ERANGE; |
| __real__ Res = HUGE_VAL; |
| __imag__ Res = HUGE_VAL; |
| } |
| else if ( isinf (denom)) |
| { |
| errno = ERANGE; |
| __real__ Res = two_R > 0 ? 1.0 : -1.0; |
| __imag__ Res = 0.0; |
| } |
| else |
| { |
| __real__ Res = sinh (two_R) / denom; |
| __imag__ Res = sin (two_I) / denom; |
| } |
| return Res; |
| } |