r128: *** empty log message ***

[ctsim.git] / libctsim / filter.cpp

diff --git a/libctsim/filter.cpp b/libctsim/filter.cpp
index bfb55e8dc4695ee5fb451c2847c3185d5e63990a..3215d6a2e27c1037ebc3a01ed385a220ccb8aa60 100644 (file)
--- 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<double> fftSignal[n];
+    complex<double> fftSignal[m_nSignalPoints];
     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);
+    //    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<double> output[], const int n, int direction)
+SignalFilter::finiteFourierTransform (const float input[], complex<double> output[], const int n, int direction)
 {
   if (direction < 0)
     direction = -1;
@@ -682,17 +672,17 @@ SignalFilter::finiteFourierTransform (const double input[], complex<double> outp
 }
 
 void
-SignalFilter::finiteFourierTransform (const double input[], complex<double> output[], int direction) const
+SignalFilter::finiteFourierTransform (const float 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 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<double> outp
       }
     }
     if (direction > 0) {
-      sumReal /= m_nPoints;
-      sumImag /= m_nPoints;
+      sumReal /= m_nSignalPoints;
+      sumImag /= m_nSignalPoints;
     }
     output[i] = complex<double> (sumReal, sumImag);
   }