From: unknown <s0042331@.dynamic.ewi.utwente.nl>
Date: Thu, 27 Mar 2008 16:41:25 +0000 (+0100)
Subject:  * Use two periods of the sine for testing instead of one and scale the values
X-Git-Url: https://git.stderr.nl/gitweb?a=commitdiff_plain;h=2af1857cd1a8eab206dbde5f5af0156d9ee9f702;p=matthijs%2Fprojects%2Fmontium-fft.git

 * Use two periods of the sine for testing instead of one and scale the values
   to prevent overflow.
---

diff --git a/FFT_support.cpp b/FFT_support.cpp
index 23d07f0..d3b5d09 100644
--- a/FFT_support.cpp
+++ b/FFT_support.cpp
@@ -68,7 +68,9 @@ void pre_run()
 	
 	for (i=0;i<PARAM_N_t;i++)
 	{
-		int value = to_fixed(sin((float)i*2*M_PI/PARAM_N_t));
+		/* We take the sine from 0 to 2*2*Pi, ie two periods. We divide 
+		 * the value by PARAM_N_t to prevent overflow. */
+		int value = to_fixed(sin((float)i*2*2*M_PI/PARAM_N_t)/PARAM_N_t);
 
 		if (i<PARAM_N_t/2)
 		{