X-Git-Url: http://git.kpe.io/?p=ctsim.git;a=blobdiff_plain;f=libctsim%2Ffilter.cpp;h=bfb55e8dc4695ee5fb451c2847c3185d5e63990a;hp=d97ca2567f989d3018e42607241dc8c70e903854;hb=e4ffe82feebf1df2ac1dd14633818eb9a739863f;hpb=00bead9fe7ab835c1584eac4ab586cc56742eaf3 diff --git a/libctsim/filter.cpp b/libctsim/filter.cpp index d97ca25..bfb55e8 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 1.5 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 @@ -37,16 +37,18 @@ * 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; @@ -54,6 +56,13 @@ SignalFilter::SignalFilter (const char* filterName, double bw, double xmin, doub 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; @@ -61,12 +70,12 @@ SignalFilter::SignalFilter (const char* filterName, double bw, double xmin, doub 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) @@ -74,6 +83,8 @@ SignalFilter::SignalFilter (const char* filterName, const char* domainName, doub 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); @@ -93,24 +104,39 @@ SignalFilter::SignalFilter (const char* filterName, const char* domainName, doub } 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); @@ -146,10 +172,12 @@ SignalFilter::init (const FilterID filterID, double bw, double xmin, double xmax 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; @@ -207,6 +235,48 @@ SignalFilter::convertFilterIDToName (const FilterID filterID) 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) { @@ -234,6 +304,32 @@ SignalFilter::convertDomainIDToName (const DomainID domain) } +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 fftSignal[n]; + 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); + } +} + + double SignalFilter::response (double x) { @@ -492,10 +588,9 @@ SignalFilter::spatialResponseAnalytic (FilterID filterID, double bw, double x, d 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)); } @@ -560,3 +655,57 @@ for (int i = 0; i < np; i++) return (sum * dx); } + +void +SignalFilter::finiteFourierTransform (const double input[], complex 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 (sumReal, sumImag); + } +} + +void +SignalFilter::finiteFourierTransform (const double 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 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 (sumReal, sumImag); + } +}