** This is part of the CTSim program
** Copyright (C) 1983-2000 Kevin Rosenberg
**
-** $Id: filter.cpp,v 1.5 2000/06/30 02:03:27 kevin Exp $
+** $Id: filter.cpp,v 1.6 2000/07/02 18:21:39 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
* int filt_type Type of filter wanted
* double bw Bandwidth of filter
* double xmin, xmax Filter limits
- * int n Number of points in filter
+ * int n Number of points in signal
* double param General input parameter to filters
* int domain FREQUENCY or SPATIAL domain wanted
* int numint Number if intervals for calculating discrete inverse fourier xform
* for spatial domain filters. For ANALYTIC solutions, use numint = 0
*/
-SignalFilter::SignalFilter (const char* filterName, double bw, double xmin, double xmax, int n, double param, const char* domainName, int numIntegral = 0)
+SignalFilter::SignalFilter (const char* filterName, const char* filterMethodName, double bw, double signalLength, int n, double param, const char* domainName, int numIntegral = 0)
{
m_vecFilter = NULL;
+ m_vecFourierCosTable = NULL;
+ m_vecFourierSinTable = NULL;
m_idFilter = convertFilterNameToID (filterName);
if (m_idFilter == FILTER_INVALID) {
m_fail = true;
m_failMessage += filterName;
return;
}
+ m_idFilterMethod = convertFilterMethodNameToID (filterMethodName);
+ if (m_idFilterMethod == FILTER_METHOD_INVALID) {
+ m_fail = true;
+ m_failMessage = "Invalid filter method name ";
+ m_failMessage += filterMethodName;
+ return;
+ }
m_idDomain = convertDomainNameToID (domainName);
if (m_idDomain == DOMAIN_INVALID) {
m_fail = true;
m_failMessage += domainName;
return;
}
- init (m_idFilter, bw, xmin, xmax, n, param, m_idDomain, numIntegral);
+ init (m_idFilter, m_idFilterMethod, bw, signalLength, n, param, m_idDomain, numIntegral);
}
-SignalFilter::SignalFilter (const FilterID filterID, double bw, double xmin, double xmax, int n, double param, const DomainID domainID, int numIntegral = 0)
+SignalFilter::SignalFilter (const FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalLength, int n, double param, const DomainID domainID, int numIntegral = 0)
{
- init (filterID, bw, xmin, xmax, n, param, domainID, numIntegral);
+ init (filterID, filterMethodID, bw, signalLength, n, param, domainID, numIntegral);
}
SignalFilter::SignalFilter (const char* filterName, const char* domainName, double bw, double param, int numIntegral = 0)
m_bw = bw;
m_nPoints = 0;
m_vecFilter = NULL;
+ m_vecFourierCosTable = NULL;
+ m_vecFourierSinTable = NULL;
m_filterParam = param;
m_numIntegral = numIntegral;
m_idFilter = convertFilterNameToID (filterName);
}
void
-SignalFilter::init (const FilterID filterID, double bw, double xmin, double xmax, int n, double param, const DomainID domainID, int numint)
+SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalLength, int n, double param, const DomainID domainID, int numint)
{
m_bw = bw;
m_idFilter = filterID;
m_idDomain = domainID;
- if (m_idFilter == FILTER_INVALID || m_idDomain == DOMAIN_INVALID) {
+ m_idFilterMethod = filterMethodID;
+ if (m_idFilter == FILTER_INVALID || m_idDomain == DOMAIN_INVALID || m_idFilterMethod == FILTER_METHOD_INVALID) {
m_fail = true;
return;
}
m_nameFilter = convertFilterIDToName (m_idFilter);
m_nameDomain = convertDomainIDToName (m_idDomain);
+ m_nameFilterMethod = convertFilterMethodIDToName (m_idFilterMethod);
m_fail = false;
- m_nPoints = n;
- m_xmin = xmin;
- m_xmax = xmax;
+ m_nSignalPoints = n;
+ m_nFilterPoints = 2 * m_nSignalPoints - 1;
+
+ m_signalLength = signalLength;
+ m_xmin = -signalLength;
+ m_xmax = signalLength;
m_numIntegral = numint;
m_filterParam = param;
m_vecFilter = new double[n];
+ if (m_idFilterMethod == FILTER_METHOD_FOURIER) {
+ int nFourier = n * n + 1;
+ double angleIncrement = (2. * PI) / n;
+ 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);
+ }
+ }
double xinc = (m_xmax - m_xmin) / (m_nPoints - 1);
SignalFilter::~SignalFilter (void)
{
delete m_vecFilter;
+ delete m_vecFourierSinTable;
+ delete m_vecFourierCosTable;
}
-SignalFilter::FilterID
+const SignalFilter::FilterID
SignalFilter::convertFilterNameToID (const char *filterName)
{
FilterID filterID = FILTER_INVALID;
return (name);
}
+const SignalFilter::FilterMethodID
+SignalFilter::convertFilterMethodNameToID (const char* const filterMethodName)
+{
+ FilterMethodID fmID = FILTER_METHOD_INVALID;
+
+ if (strcasecmp (filterMethodName, FILTER_METHOD_CONVOLUTION_STR) == 0)
+ fmID = FILTER_METHOD_CONVOLUTION;
+ else if (strcasecmp (filterMethodName, FILTER_METHOD_FOURIER_STR) == 0)
+ 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;
+
+ return (fmID);
+}
+
+const char *
+SignalFilter::convertFilterMethodIDToName (const FilterMethodID fmID)
+{
+ const char *name = "";
+
+ if (fmID == FILTER_METHOD_CONVOLUTION)
+ return (FILTER_METHOD_CONVOLUTION_STR);
+ else if (fmID == FILTER_METHOD_FOURIER)
+ 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);
+
+ return (name);
+}
+
const SignalFilter::DomainID
SignalFilter::convertDomainNameToID (const char* const domainName)
{
}
+void
+SignalFilter::filterSignal (const double input[], double output[], double dx, const int n) const
+{
+ if (m_idFilterMethod == FILTER_METHOD_CONVOLUTION) {
+ for (int i = 0; i < n; i++)
+ output[i] = convolve (input, dx, i, n);
+ } else if (m_idFilterMethod == FILTER_METHOD_FOURIER) {
+ complex<double> fftSignal[n];
+ complex<double> complexOutput;
+ finiteFourierTransform (input, fftSignal, 1);
+ finiteFourierTransform (fftSignal, complexOutput, -1);
+ for (int i = 0; i < n; i++)
+ output[i] = complexOutput[i].mag();
+ }
+}
+
+void
+SignalFilter::filterSignal (const float input[], double output[], double dx, const int n) const
+{
+ if (m_idFilterMethod == FILTER_METHOD_CONVOLUTION) {
+ for (int i = 0; i < n; i++)
+ output[i] = convolve (input, dx, i, n);
+ }
+}
+
+
double
SignalFilter::response (double x)
{
double
SignalFilter::integral_abscos (double u, double w)
{
- if (fabs (u) > F_EPSILON)
- return (cos(u * w) - 1) / (u * u) + w / u * sin (u * w);
- else
- return (w * w / 2);
+ return (fabs (u) > F_EPSILON
+ ? (cos(u * w) - 1) / (u * u) + w / u * sin (u * w)
+ : (w * w / 2));
}
return (sum * dx);
}
+
+void
+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;
+ 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;
+ sumReal += input[i] * cos(angle);
+ sumImag += input[i] * sin(angle);
+ }
+ if (direction > 0) {
+ sumReal /= n;
+ sumImag /= n;
+ }
+ output[i] = complex<double> (sumReal, sumImag);
+ }
+}
+
+void
+SignalFilter::finiteFourierTransform (const double input[], complex<double> output[], int direction) const
+{
+ if (direction < 0)
+ direction = -1;
+ else
+ direction = 1;
+
+ double angleIncrement = 2 * PI / m_nPoints;
+ for (int i = 0; i < m_nPoints; i++) {
+ double sumReal = 0, sumImag = 0;
+ for (int j = 0; j < m_nPoints; j++) {
+ int tableIndex = i * j;
+ if (direction > 0) {
+ sumReal += input[i] * m_vecFourierCosTable[tableIndex];
+ sumImag += input[i] * m_vecFourierSinTable[tableIndex];
+ } else {
+ sumReal += input[i] * m_vecFourierCosTable[tableIndex];
+ sumImag -= input[i] * m_vecFourierSinTable[tableIndex];
+ }
+ }
+ if (direction > 0) {
+ sumReal /= m_nPoints;
+ sumImag /= m_nPoints;
+ }
+ output[i] = complex<double> (sumReal, sumImag);
+ }
+}
projects / ctsim.git / blobdiff