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Code Issues Releases Wiki Activity

Restructure to a switch statement (John Clark)

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This commit is contained in:
james.k.crook 2011-02-03 12:35:31 +00:00
parent df6e56a57e
commit fa8d42e664
1 changed files with 22 additions and 28 deletions
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50
src/FFT.cpp
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@ -519,49 +519,45 @@ void WindowFunc(int whichFunction, int NumSamples, float *in)
int i;
double A;
if (whichFunction == 1) {
switch( whichFunction )
{
case 1:
// Bartlett (triangular) window
for (i = 0; i < NumSamples / 2; i++) {
in[i] *= (i / (float) (NumSamples / 2));
in[i + (NumSamples / 2)] *=
(1.0 - (i / (float) (NumSamples / 2)));
}
}
if (whichFunction == 2) {
break;
case 2:
// Hamming
for (i = 0; i < NumSamples; i++)
in[i] *= 0.54 - 0.46 * cos(2 * M_PI * i / (NumSamples - 1));
}
if (whichFunction == 3) {
break;
case 3:
// Hanning
for (i = 0; i < NumSamples; i++)
in[i] *= 0.50 - 0.50 * cos(2 * M_PI * i / (NumSamples - 1));
}
if (whichFunction == 4) {
break;
case 4:
// Blackman
for (i = 0; i < NumSamples; i++) {
in[i] *= 0.42 - 0.5 * cos (2 * M_PI * i / (NumSamples - 1)) + 0.08 * cos (4 * M_PI * i / (NumSamples - 1));
}
}
if (whichFunction == 5) {
break;
case 5:
// Blackman-Harris
for (i = 0; i < NumSamples; i++) {
in[i] *= 0.35875 - 0.48829 * cos(2 * M_PI * i /(NumSamples-1)) + 0.14128 * cos(4 * M_PI * i/(NumSamples-1)) - 0.01168 * cos(6 * M_PI * i/(NumSamples-1));
}
}
if (whichFunction == 6) {
break;
case 6:
// Welch
for (i = 0; i < NumSamples; i++) {
in[i] *= 4*i/(float)NumSamples*(1-(i/(float)NumSamples));
}
}
if (whichFunction == 7) {
break;
case 7:
// Gaussian (a=2.5)
// Precalculate some values, and simplify the fmla to try and reduce overhead
A=-2*2.5*2.5;
@ -572,19 +568,16 @@ void WindowFunc(int whichFunction, int NumSamples, float *in)
// reduced
in[i] *= exp(A*(0.25 + ((i/(float)NumSamples)*(i/(float)NumSamples)) - (i/(float)NumSamples)));
}
}
if (whichFunction == 8) {
break;
case 8:
// Gaussian (a=3.5)
A=-2*3.5*3.5;
for (i = 0; i < NumSamples; i++) {
// reduced
in[i] *= exp(A*(0.25 + ((i/(float)NumSamples)*(i/(float)NumSamples)) - (i/(float)NumSamples)));
}
}
if (whichFunction == 9) {
break;
case 9:
// Gaussian (a=4.5)
A=-2*4.5*4.5;
@ -592,9 +585,10 @@ void WindowFunc(int whichFunction, int NumSamples, float *in)
// reduced
in[i] *= exp(A*(0.25 + ((i/(float)NumSamples)*(i/(float)NumSamples)) - (i/(float)NumSamples)));
}
break;
default:
fprintf(stderr,"FFT::WindowFunc - Invalid window function: %d\n",whichFunction);
}
}
// Indentation settings for Vim and Emacs and unique identifier for Arch, a