cadencii.fft.cdft C# (CSharp) Method

        public static void cdft( int n, int isgn, double* a, int* ip, double* w ) {
            //void makewt(int nw, int *ip, double *w);
            //void cftfsub(int n, double *a, int *ip, int nw, double *w);
            //void cftbsub(int n, double *a, int *ip, int nw, double *w);
            int nw;

            nw = ip[0];
            if ( n > (nw << 2) ) {
                nw = n >> 2;
                makewt( nw, ip, w );
            }
            if ( isgn >= 0 ) {
                cftfsub( n, a, ip, nw, w );
            } else {
                cftbsub( n, a, ip, nw, w );
            }
        }