# MATH_MakeFFTSinTable

## C Specification

      #include <nitro/math/fft.h>

      void MATH_MakeFFTSinTable( fx16* sinTable, u32 nShift );

## Arguments

sinTable | Pointer to the table of sine values.
nShift | The value obtained by taking the base 2 logarithm for the data length.

## Return Values

None.

## Description

This creates a sine value table required for fast Fourier transforms.

In the explanation below, the value 2nShift (2 to the nShift power) is represented as N. A pointer to an fx16 type array of length of N*3/4 is passed to sinTable. Calling this function causes a fx16 type sin value to be assigned in the sinTable that satisfies `sinTable[k] = sin( (2π/N) * k ) (k = 0, 1,..., N*3/4-1)`. In doing so, the FX_SinIdx function is used.

## See Also

FX_SinIdx, MATH_FFT, MATH_IFFT, MATH_FFTReal, MATH_IFFTReal

## Revision History

07/21/2005 Corrected description of `sinTable`.
05/13/2005 Initial version.