/**
* Performs a forward transform on the passed buffers.
*
* @param buffReal the real part of the time domain signal to transform
* @param buffImag the imaginary part of the time domain signal to transform
*/
public void forward(float[] buffReal, float[] buffImag) {
if (buffReal.length != timeSize || buffImag.length != timeSize) {
Minim.error("FFT.forward: The length of the passed buffers must be equal to timeSize().");
return;
}
setComplex(buffReal, buffImag);
bitReverseComplex();
fft();
fillSpectrum();
}
@Override
public void forward(float[] buffer) {
if (buffer.length != timeSize) {
Minim.error(
"FFT.forward: The length of the passed sample buffer " + "must be equal to timeSize().");
return;
}
doWindow(buffer);
// copy samples to real/imag in bit-reversed order
bitReverseSamples(buffer);
// perform the fft
fft();
// fill the spectrum buffer with amplitudes
fillSpectrum();
}
@Override
public void inverse(float[] buffer) {
if (buffer.length > real.length) {
Minim.error("FFT.inverse: the passed array's length must equal FFT.timeSize().");
return;
}
// conjugate
for (int i = 0; i < timeSize; i++) {
imag[i] *= -1;
}
bitReverseComplex();
fft();
// copy the result in real into buffer, scaling as we do
for (int i = 0; i < buffer.length; i++) {
buffer[i] = real[i] / real.length;
}
}