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+#include "fftease.h" /* unconvert essentially undoes what convert does, i.e., it turns N2+1 PAIRS of amplitude and frequency values in C into N2 PAIR of complex spectrum data (in rfft format) in output array S; sampling rate R and interpolation factor I are used to recompute phase values from frequencies */ void leanunconvert( float *C, float *S, int N2 ) { double cos(), sin(); int real, imag, amp, phase; register int i; for ( i = 0; i <= N2; i++ ) { imag = phase = ( real = amp = i<<1 ) + 1; S[real] = *(C+amp) * cos( *(C+phase) ); if ( i != N2 ) S[imag] = -*(C+amp) * sin( *(C+phase) ); } } \ No newline at end of file