X-Git-Url: http://git.kpe.io/?p=ctsim.git;a=blobdiff_plain;f=libctsim%2Ffilter.cpp;h=3215d6a2e27c1037ebc3a01ed385a220ccb8aa60;hp=bfb55e8dc4695ee5fb451c2847c3185d5e63990a;hb=53c732778ed19ac5231bb17c7e5bd4d2201d9456;hpb=e4ffe82feebf1df2ac1dd14633818eb9a739863f diff --git a/libctsim/filter.cpp b/libctsim/filter.cpp index bfb55e8..3215d6a 100644 --- a/libctsim/filter.cpp +++ b/libctsim/filter.cpp @@ -9,7 +9,7 @@ ** This is part of the CTSim program ** Copyright (C) 1983-2000 Kevin Rosenberg ** -** $Id: filter.cpp,v 1.6 2000/07/02 18:21:39 kevin Exp $ +** $Id: filter.cpp,v 1.7 2000/07/03 11:02:06 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 @@ -32,11 +32,11 @@ * SignalFilter::SignalFilter Construct a signal * * SYNOPSIS - * f = SignalFilter (filt_type, bw, xmin, xmax, n, param, domain, analytic) + * f = SignalFilter (filt_type, bw, filterMin, filterMax, n, param, domain, analytic) * double f Generated filter vector * int filt_type Type of filter wanted * double bw Bandwidth of filter - * double xmin, xmax Filter limits + * double filterMin, filterMax Filter limits * int n Number of points in signal * double param General input parameter to filters * int domain FREQUENCY or SPATIAL domain wanted @@ -44,7 +44,7 @@ * for spatial domain filters. For ANALYTIC solutions, use numint = 0 */ -SignalFilter::SignalFilter (const char* filterName, const char* filterMethodName, double bw, double signalLength, int n, double param, const char* domainName, int numIntegral = 0) +SignalFilter::SignalFilter (const char* filterName, const char* filterMethodName, double bw, double signalIncrement, int n, double param, const char* domainName, int numIntegral = 0) { m_vecFilter = NULL; m_vecFourierCosTable = NULL; @@ -70,18 +70,19 @@ SignalFilter::SignalFilter (const char* filterName, const char* filterMethodName m_failMessage += domainName; return; } - init (m_idFilter, m_idFilterMethod, bw, signalLength, n, param, m_idDomain, numIntegral); + init (m_idFilter, m_idFilterMethod, bw, signalIncrement, n, param, m_idDomain, numIntegral); } -SignalFilter::SignalFilter (const FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalLength, int n, double param, const DomainID domainID, int numIntegral = 0) +SignalFilter::SignalFilter (const FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalIncrement, int n, double param, const DomainID domainID, int numIntegral = 0) { - init (filterID, filterMethodID, bw, signalLength, n, param, domainID, numIntegral); + init (filterID, filterMethodID, bw, signalIncrement, 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_nSignalPoints = 0; + m_nFilterPoints = 0; m_vecFilter = NULL; m_vecFourierCosTable = NULL; m_vecFourierSinTable = NULL; @@ -104,7 +105,7 @@ SignalFilter::SignalFilter (const char* filterName, const char* domainName, doub } void -SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalLength, int n, double param, const DomainID domainID, int numint) +SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalIncrement, int n, double param, const DomainID domainID, int numint) { m_bw = bw; m_idFilter = filterID; @@ -121,12 +122,13 @@ SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID m_nSignalPoints = n; m_nFilterPoints = 2 * m_nSignalPoints - 1; - m_signalLength = signalLength; - m_xmin = -signalLength; - m_xmax = signalLength; + m_signalInc = signalIncrement; + m_filterMin = -signalIncrement * (m_nSignalPoints - 1); + m_filterMax = signalIncrement * (m_nSignalPoints - 1); + m_filterInc = (m_filterMax - m_filterMin) / (m_nFilterPoints - 1); m_numIntegral = numint; m_filterParam = param; - m_vecFilter = new double[n]; + m_vecFilter = new double[ m_nFilterPoints ]; if (m_idFilterMethod == FILTER_METHOD_FOURIER) { int nFourier = n * n + 1; double angleIncrement = (2. * PI) / n; @@ -138,12 +140,10 @@ SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID } } - double xinc = (m_xmax - m_xmin) / (m_nPoints - 1); - if (m_idFilter == FILTER_SHEPP) { double a = 2 * m_bw; double c = - 4. / (a * a); - int center = (m_nPoints - 1) / 2; + int center = (m_nFilterPoints - 1) / 2; int sidelen = center; m_vecFilter[center] = 4. / (a * a); @@ -152,12 +152,12 @@ SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID } else if (m_idDomain == DOMAIN_FREQUENCY) { double x; int i; - for (x = m_xmin, i = 0; i < m_nPoints; x += xinc, i++) + for (x = m_filterMin, i = 0; i < m_nFilterPoints; x += m_filterInc, i++) m_vecFilter[i] = frequencyResponse (x, param); } else if (m_idDomain == DOMAIN_SPATIAL) { double x; int i; - for (x = m_xmin, i = 0; i < m_nPoints; x += xinc, i++) + for (x = m_filterMin, i = 0; i < m_nFilterPoints; x += m_filterInc, i++) if (numint == 0) m_vecFilter[i] = spatialResponseAnalytic (x, param); else @@ -305,31 +305,21 @@ SignalFilter::convertDomainIDToName (const DomainID domain) void -SignalFilter::filterSignal (const double input[], double output[], double dx, const int n) const +SignalFilter::filterSignal (const float input[], double output[]) const { if (m_idFilterMethod == FILTER_METHOD_CONVOLUTION) { - for (int i = 0; i < n; i++) - output[i] = convolve (input, dx, i, n); + 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 fftSignal[n]; + complex fftSignal[m_nSignalPoints]; complex 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); + // finiteFourierTransform (fftSignal, complexOutput, -1); + // for (int i = 0; i < m_nSignalPoints; i++) + // output[i] = complexOutput[i].hypot(); } } - double SignalFilter::response (double x) { @@ -657,7 +647,7 @@ for (int i = 0; i < np; i++) void -SignalFilter::finiteFourierTransform (const double input[], complex output[], const int n, int direction) +SignalFilter::finiteFourierTransform (const float input[], complex output[], const int n, int direction) { if (direction < 0) direction = -1; @@ -682,17 +672,17 @@ SignalFilter::finiteFourierTransform (const double input[], complex outp } void -SignalFilter::finiteFourierTransform (const double input[], complex output[], int direction) const +SignalFilter::finiteFourierTransform (const float input[], complex 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 angleIncrement = 2 * PI / m_nSignalPoints; + for (int i = 0; i < m_nSignalPoints; i++) { double sumReal = 0, sumImag = 0; - for (int j = 0; j < m_nPoints; j++) { + for (int j = 0; j < m_nSignalPoints; j++) { int tableIndex = i * j; if (direction > 0) { sumReal += input[i] * m_vecFourierCosTable[tableIndex]; @@ -703,8 +693,8 @@ SignalFilter::finiteFourierTransform (const double input[], complex outp } } if (direction > 0) { - sumReal /= m_nPoints; - sumImag /= m_nPoints; + sumReal /= m_nSignalPoints; + sumImag /= m_nSignalPoints; } output[i] = complex (sumReal, sumImag); }