From c394d751491782dfe485b0929c0e1343674872f4 Mon Sep 17 00:00:00 2001 From: ymherklotz Date: Mon, 5 Mar 2018 13:17:54 +0000 Subject: Modified dft --- Project/TestCode/dft.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) (limited to 'Project/TestCode') diff --git a/Project/TestCode/dft.c b/Project/TestCode/dft.c index 9ffcfbe..d0dca12 100644 --- a/Project/TestCode/dft.c +++ b/Project/TestCode/dft.c @@ -13,26 +13,35 @@ float x[] = {0, 0, 2, 3, 4, 0, 0, 0}; Complex X[N]; float x_out[N]; -void dft() { - int n, k; +void dft(int N, Complex *X) { + int i, n, k; + Complex x[N]; + for(i = 0; i < N; ++i) { + x[i] = X[i]; + } for(k = 0; k < N; ++k) { X[k].r = 0.f; X[k].i = 0.f; for(n = 0; n < N; ++n) { - X[k].r += x[n] * cos(2 * E_PI * k * n / N); - X[k].i -= x[n] * sin(2 * E_PI * k * n / N); + X[k].r += x[n].r * cos(2 * E_PI * k * n / N); + X[k].i -= x[n].r * sin(2 * E_PI * k * n / N); } } } -void idft() { - int n, k; +void idft(int N, Complex *X) { + int i, n, k; + Complex x[N]; + for(i = 0; i < N; ++i) { + x[i] = X[i]; + } for(n = 0; n < N; ++n) { - x_out[n] = 0.f; + X[n].i = 0.f; + X[n].r = 0.f; for(k = 0; k < N; ++k) { - x_out[n] += X[k].r * cos(2 * E_PI * k * n / N) - X[k].i * sin(2 * E_PI * k * n / N); + X[n].r += x[k].r * cos(2 * E_PI * k * n / N) - x[k].i * sin(2 * E_PI * k * n / N); } - x_out[n] /= N; + X[n] /= N; } } -- cgit