diff Simulation/createFiltNoise.m @ 0:ab043bd3b162 tip

First commit

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Simulation/createFiltNoise.m	Mon Jun 11 17:42:13 2012 +0100
@@ -0,0 +1,60 @@
+function [output]=createFiltNoise(input,centreFreq,bandWidth,filterOrder,Fs)
+
+% create filtered noise for bandwidth simulation
+%
+% Input:
+%   - input: input to be filtered
+%   - centreFreq: centre frequency or cutoff frequency
+%   - bandWidth: width of filter
+%   - filterOrder: order of butterworth filter (4)
+%   - Fs: sampling frequency (44100)
+%
+% Output:
+%   - output: array
+%
+
+% Developer:  - Alice Clifford ([e-mail])
+
+
+
+if centreFreq==0  %LOW PASS FILTER FOR CENTRE FREQ ==0
+    
+    cutoffFreq=bandWidth;
+    
+    normCutFreq=(cutoffFreq/(Fs/2));
+    
+    [b,a]=butter(filterOrder,normCutFreq,'low');
+    
+    output=filter(b,a,input);
+    
+    
+    
+elseif centreFreq==22050 %HIGH PASS FILTER FOR CENTREFREQ == FS/2
+    
+    cutoffFreq=(Fs/2)-bandWidth;
+    
+    normCutFreq=(cutoffFreq/(Fs/2));
+    
+    [b,a]=butter(filterOrder,normCutFreq,'high'); %HIGH PASS FILTER
+    
+    output=filter(b,a,input);
+    
+    
+    
+    
+else% %BAND PASS - NEED LOW AND HIGH PASS
+    
+    lowBandFreq=centreFreq-(bandWidth/2);
+    highBandFreq=centreFreq+(bandWidth/2);
+    
+    highNormBandFreq=(highBandFreq/(Fs/2));
+    lowNormBandFreq=(lowBandFreq/(Fs/2));
+    
+    
+    [b,a]=butter(filterOrder,[lowNormBandFreq highNormBandFreq]);
+    
+    
+    
+    output=filter(b,a,input);
+    
+end
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