** This is part of the CTSim program
** Copyright (C) 1983-2000 Kevin Rosenberg
**
-** $Id: filter.cpp,v 1.12 2000/07/05 17:59:26 kevin Exp $
+** $Id: filter.cpp,v 1.13 2000/07/06 08:30:30 kevin Exp $
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License (version 2) as
* for spatial domain filters. For ANALYTIC solutions, use numint = 0
*/
-SignalFilter::SignalFilter (const char* filterName, const char* filterMethodName, double bw, double signalIncrement, int nSignalPoints, double param, const char* domainName, int numIntegral = 0)
+SignalFilter::SignalFilter (const char* filterName, const char* filterMethodName, double bw, double signalIncrement, int nSignalPoints, double param, const char* domainName, int zeropad = 0, int numIntegral = 0)
{
m_vecFilter = NULL;
m_vecFourierCosTable = NULL;
m_vecFourierSinTable = NULL;
+ m_vecFftInput = NULL;
m_idFilter = convertFilterNameToID (filterName);
if (m_idFilter == FILTER_INVALID) {
m_fail = true;
m_failMessage += domainName;
return;
}
- init (m_idFilter, m_idFilterMethod, bw, signalIncrement, nSignalPoints, param, m_idDomain, numIntegral);
+ init (m_idFilter, m_idFilterMethod, bw, signalIncrement, nSignalPoints, param, m_idDomain, zeropad, numIntegral);
}
-SignalFilter::SignalFilter (const FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalIncrement, int nSignalPoints, double param, const DomainID domainID, int numIntegral = 0)
+SignalFilter::SignalFilter (const FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalIncrement, int nSignalPoints, double param, const DomainID domainID, int zeropad = 0, int numIntegral = 0)
{
- init (filterID, filterMethodID, bw, signalIncrement, nSignalPoints, param, domainID, numIntegral);
+ init (filterID, filterMethodID, bw, signalIncrement, nSignalPoints, param, domainID, zeropad, numIntegral);
}
SignalFilter::SignalFilter (const char* filterName, const char* domainName, double bw, double param, int numIntegral = 0)
m_vecFilter = NULL;
m_vecFourierCosTable = NULL;
m_vecFourierSinTable = NULL;
+ m_vecFftInput = NULL;
m_filterParam = param;
m_numIntegral = numIntegral;
m_idFilter = convertFilterNameToID (filterName);
}
void
-SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalIncrement, int nSignalPoints, double param, const DomainID domainID, int numint)
+SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalIncrement, int nSignalPoints, double param, const DomainID domainID, int zeropad, int numint)
{
m_bw = bw;
m_idFilter = filterID;
m_nSignalPoints = nSignalPoints;
m_signalInc = signalIncrement;
m_filterParam = param;
-
- if (m_idFilterMethod == FILTER_METHOD_FOURIER) {
- int nFourier = m_nSignalPoints * m_nSignalPoints + 1;
- double angleIncrement = (2. * PI) / m_nSignalPoints;
- m_vecFourierCosTable = new double[ nFourier ];
- m_vecFourierSinTable = new double[ nFourier ];
- for (int i = 0; i < nFourier; i++) {
- m_vecFourierCosTable[i] = cos (angleIncrement * i);
- m_vecFourierSinTable[i] = sin (angleIncrement * i);
- }
- m_nFilterPoints = m_nSignalPoints;
- m_filterMin = -1. / (2 * m_signalInc);
- m_filterMax = 1. / (2 * m_signalInc);
- m_filterInc = (m_filterMax - m_filterMin) / m_nFilterPoints;
- m_vecFilter = new double [m_nFilterPoints];
- int halfFilter = m_nFilterPoints / 2;
- for (int i = 0; i < halfFilter; i++)
- m_vecFilter[i] = static_cast<double>(i) / (halfFilter - 1) / (2 * m_signalInc);
- for (int i = 0; i < halfFilter; i++)
- m_vecFilter[m_nFilterPoints - i - 1] = static_cast<double>(i+1) / (halfFilter - 1) / (2 * m_signalInc);
- if (halfFilter % 2) // odd
- m_vecFilter[halfFilter] = 1 / (2 * m_signalInc);
- } else if (m_idFilterMethod == FILTER_METHOD_FFT || m_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_2 || m_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_4) {
+ m_zeropad = zeropad;
+
+ m_vecFourierCosTable = NULL;
+ m_vecFourierSinTable = NULL;
+ m_vecFilter = NULL;
+ m_vecFftInput = NULL;
+
+ if (m_idFilterMethod == FILTER_METHOD_FFT)
+ m_idFilterMethod = FILTER_METHOD_FFTW;
+
+ if (m_idFilterMethod == FILTER_METHOD_FOURIER || m_idFilterMethod == FILTER_METHOD_FFT || m_idFilterMethod == FILTER_METHOD_FFTW) {
m_nFilterPoints = m_nSignalPoints;
- if (m_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_2 || m_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_4) {
+ if (m_zeropad > 0) {
double logBase2 = log(m_nSignalPoints) / log(2);
- int nextPowerOf2 = static_cast<int>(floor(logBase2)) + 1;
- if (m_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_4)
- nextPowerOf2++;
+ int nextPowerOf2 = static_cast<int>(floor(logBase2));
if (logBase2 != floor(logBase2))
nextPowerOf2++;
+ nextPowerOf2 += m_zeropad;
m_nFilterPoints = 1 << nextPowerOf2;
cout << "nFilterPoints = " << m_nFilterPoints << endl;
}
m_filterInc = (m_filterMax - m_filterMin) / m_nFilterPoints;
m_vecFilter = new double [m_nFilterPoints];
int halfFilter = m_nFilterPoints / 2;
- for (int i = 0; i < halfFilter; i++)
- m_vecFilter[i] = static_cast<double>(i) / (halfFilter - 1) / (2 * m_signalInc) / m_nSignalPoints;
- for (int i = 0; i < halfFilter; i++)
- m_vecFilter[m_nFilterPoints - i - 1] = static_cast<double>(i+1) / (halfFilter - 1) / (2 * m_signalInc) / m_nSignalPoints;
- if (halfFilter % 2) // odd
- m_vecFilter[halfFilter] = 1 / (2 * m_signalInc) / m_nSignalPoints;
+ for (int i = 0; i <= halfFilter; i++)
+ m_vecFilter[i] = static_cast<double>(i) / halfFilter/ (2. * m_signalInc);
+ for (int i = 1; i <= halfFilter; i++)
+ m_vecFilter[m_nFilterPoints - i] = static_cast<double>(i) / halfFilter / (2. * m_signalInc);
+ }
+
+ // precalculate sin and cosine tables for fourier transform
+ if (m_idFilterMethod == FILTER_METHOD_FOURIER) {
+ int nFourier = m_nFilterPoints * m_nFilterPoints + 1;
+ double angleIncrement = (2. * PI) / m_nFilterPoints;
+ m_vecFourierCosTable = new double[ nFourier ];
+ m_vecFourierSinTable = new double[ nFourier ];
+ double angle = 0;
+ for (int i = 0; i < nFourier; i++) {
+ m_vecFourierCosTable[i] = cos (angle);
+ m_vecFourierSinTable[i] = sin (angle);
+ angle += angleIncrement;
+ }
+ }
#if HAVE_FFTW
+ if (m_idFilterMethod == FILTER_METHOD_FFTW) {
+ for (int i = 0; i < m_nFilterPoints; i++) //fftw uses unnormalized fft
+ m_vecFilter[i] /= m_nFilterPoints;
+
m_planForward = fftw_create_plan (m_nFilterPoints, FFTW_FORWARD, FFTW_ESTIMATE);
m_planBackward = fftw_create_plan (m_nFilterPoints, FFTW_BACKWARD, FFTW_ESTIMATE);
-#endif
+ m_vecFftInput = new fftw_complex [ m_nFilterPoints ];
+ for (int i = 0; i < m_nFilterPoints; i++)
+ m_vecFftInput[i].re = m_vecFftInput[i].im = 0;
}
+#endif
if (m_idFilterMethod == FILTER_METHOD_CONVOLUTION) {
m_nFilterPoints = 2 * m_nSignalPoints - 1;
SignalFilter::~SignalFilter (void)
{
- delete m_vecFilter;
- delete m_vecFourierSinTable;
- delete m_vecFourierCosTable;
+ delete [] m_vecFilter;
+ delete [] m_vecFourierSinTable;
+ delete [] m_vecFourierCosTable;
+ delete [] m_vecFftInput;
#if HAVE_FFTW
- if (m_idFilterMethod == FILTER_METHOD_FFT) {
+ if (m_idFilterMethod == FILTER_METHOD_FFTW) {
fftw_destroy_plan(m_planForward);
fftw_destroy_plan(m_planBackward);
}
fmID = FILTER_METHOD_FOURIER;
else if (strcasecmp (filterMethodName, FILTER_METHOD_FFT_STR) == 0)
fmID = FILTER_METHOD_FFT;
- else if (strcasecmp (filterMethodName, FILTER_METHOD_FFT_ZEROPAD_2_STR) == 0)
- fmID = FILTER_METHOD_FFT_ZEROPAD_2;
- else if (strcasecmp (filterMethodName, FILTER_METHOD_FFT_ZEROPAD_4_STR) == 0)
- fmID = FILTER_METHOD_FFT_ZEROPAD_4;
- else if (strcasecmp (filterMethodName, FILTER_METHOD_FFT_ZEROPAD_6_STR) == 0)
- fmID = FILTER_METHOD_FFT_ZEROPAD_6;
+ else if (strcasecmp (filterMethodName, FILTER_METHOD_FFTW_STR) == 0)
+ fmID = FILTER_METHOD_FFTW;
return (fmID);
}
return (FILTER_METHOD_FOURIER_STR);
else if (fmID == FILTER_METHOD_FFT)
return (FILTER_METHOD_FFT_STR);
- else if (fmID == FILTER_METHOD_FFT_ZEROPAD_2)
- return (FILTER_METHOD_FFT_ZEROPAD_2_STR);
- else if (fmID == FILTER_METHOD_FFT_ZEROPAD_4)
- return (FILTER_METHOD_FFT_ZEROPAD_4_STR);
- else if (fmID == FILTER_METHOD_FFT_ZEROPAD_6)
- return (FILTER_METHOD_FFT_ZEROPAD_6_STR);
+ else if (fmID == FILTER_METHOD_FFTW)
+ return (FILTER_METHOD_FFTW_STR);
return (name);
}
for (int i = 0; i < m_nSignalPoints; i++)
output[i] = convolve (input, m_signalInc, i, m_nSignalPoints);
} else if (m_idFilterMethod == FILTER_METHOD_FOURIER) {
- complex<double> fftSignal[m_nSignalPoints];
- complex<double> complexOutput[m_nSignalPoints];
- complex<double> filteredSignal[m_nSignalPoints];
- finiteFourierTransform (input, fftSignal, m_nSignalPoints, -1);
- dotProduct (m_vecFilter, fftSignal, filteredSignal, m_nSignalPoints);
- finiteFourierTransform (filteredSignal, complexOutput, m_nSignalPoints, 1);
+ complex<double> fftSignal[m_nFilterPoints];
+ complex<double> complexOutput[m_nFilterPoints];
+ complex<double> filteredSignal[m_nFilterPoints];
+ double inputSignal[m_nFilterPoints];
+ for (int i = 0; i < m_nSignalPoints; i++)
+ inputSignal[i] = input[i];
+ for (int i = m_nSignalPoints; i < m_nFilterPoints; i++)
+ inputSignal[i] = 0; // zeropad
+ finiteFourierTransform (inputSignal, fftSignal, m_nFilterPoints, -1);
+ dotProduct (m_vecFilter, fftSignal, filteredSignal, m_nFilterPoints);
+ finiteFourierTransform (filteredSignal, complexOutput, m_nFilterPoints, 1);
for (int i = 0; i < m_nSignalPoints; i++)
output[i] = complexOutput[i].real();
- } else if (m_idFilterMethod == FILTER_METHOD_FFT || FILTER_METHOD_FFT_ZEROPAD_2 || FILTER_METHOD_FFT_ZEROPAD_4) {
+ }
#if HAVE_FFTW
- fftw_complex in[m_nFilterPoints], out[m_nFilterPoints];
- for (int i = 0; i < m_nSignalPoints; i++) {
- in[i].re = input[i];
- in[i].im = 0;
- }
- for (int i = m_nSignalPoints; i < m_nFilterPoints; i++) {
- in[i].re = in[i].im = 0; // ZeroPad
- }
- fftw_one(m_planForward, in, out);
- for (int i = 0; i < m_nFilterPoints; i++) {
- out[i].re = m_vecFilter[i] * out[i].re;
- out[i].im = m_vecFilter[i] * out[i].im;
- }
- fftw_one(m_planBackward, out, in);
- for (int i = 0; i < m_nSignalPoints; i++)
- output[i] = in[i].re;
+ else if (m_idFilterMethod == FILTER_METHOD_FFTW) {
+ for (int i = 0; i < m_nSignalPoints; i++)
+ m_vecFftInput[i].re = input[i];
+
+ fftw_complex out[m_nFilterPoints];
+ fftw_one(m_planForward, m_vecFftInput, out);
+ for (int i = 0; i < m_nFilterPoints; i++) {
+ out[i].re = m_vecFilter[i] * out[i].re;
+ out[i].im = m_vecFilter[i] * out[i].im;
+ }
+ fftw_complex outFiltered[m_nFilterPoints];
+ fftw_one(m_planBackward, out, outFiltered);
+ for (int i = 0; i < m_nSignalPoints; i++)
+ output[i] = outFiltered[i].re;
}
#endif
}
void
-SignalFilter::finiteFourierTransform (const float input[], complex<double> output[], const int n, int direction)
+SignalFilter::finiteFourierTransform (const double input[], complex<double> output[], const int n, int direction)
{
if (direction < 0)
direction = -1;
else
direction = 1;
- double angleIncrement = 2 * PI / n;
+ double angleIncrement = direction * 2 * PI / n;
for (int i = 0; i < n; i++) {
double sumReal = 0;
double sumImag = 0;
for (int j = 0; j < n; j++) {
- double angle = i * j * angleIncrement * direction;
+ double angle = i * j * angleIncrement;
sumReal += input[j] * cos(angle);
sumImag += input[j] * sin(angle);
}
}
void
-SignalFilter::finiteFourierTransform (const float input[], complex<double> output[], int direction) const
+SignalFilter::finiteFourierTransform (const double input[], complex<double> output[], int direction) const
{
if (direction < 0)
direction = -1;
else
direction = 1;
- for (int i = 0; i < m_nSignalPoints; i++) {
+ for (int i = 0; i < m_nFilterPoints; i++) {
double sumReal = 0, sumImag = 0;
- for (int j = 0; j < m_nSignalPoints; j++) {
+ for (int j = 0; j < m_nFilterPoints; j++) {
int tableIndex = i * j;
if (direction > 0) {
sumReal += input[i] * m_vecFourierCosTable[tableIndex];
}
}
if (direction < 0) {
- sumReal /= m_nSignalPoints;
- sumImag /= m_nSignalPoints;
+ sumReal /= m_nFilterPoints;
+ sumImag /= m_nFilterPoints;
}
output[i] = complex<double> (sumReal, sumImag);
}
projects / ctsim.git / blobdiff