**diff options**

Diffstat (limited to 'include/ffts.h')

-rw-r--r-- | include/ffts.h | 20 |

1 files changed, 16 insertions, 4 deletions

diff --git a/include/ffts.h b/include/ffts.h index d187e36..cc85a88 100644 --- a/include/ffts.h +++ b/include/ffts.h @@ -56,12 +56,22 @@ extern "C" { # endif #endif -#define POSITIVE_SIGN 1 -#define NEGATIVE_SIGN -1 +/* The direction of the transform + (i.e, the sign of the exponent in the transform.) +*/ +#define FFTS_FORWARD (-1) +#define FFTS_BACKWARD (+1) struct _ffts_plan_t; typedef struct _ffts_plan_t ffts_plan_t; +/* Complex data is stored in the interleaved format + (i.e, the real and imaginary parts composing each + element of complex data are stored adjacently in memory) + + The multi-dimensional arrays passed are expected to be + stored as a single contiguous block in row-major order +*/ FFTS_API ffts_plan_t* ffts_init_1d(size_t N, int sign); @@ -71,8 +81,10 @@ ffts_init_2d(size_t N1, size_t N2, int sign); FFTS_API ffts_plan_t* ffts_init_nd(int rank, size_t *Ns, int sign); -/* For real transforms, sign == -1 implies a real-to-complex forwards tranform, - and sign == 1 implies a complex-to-real backwards transform. +/* For real transforms, sign == FFTS_FORWARD implies a real-to-complex + forwards tranform, and sign == FFTS_BACKWARD implies a complex-to-real + backwards transform. + The output of a real-to-complex transform is N/2+1 complex numbers, where the redundant outputs have been omitted. */ |