X-Git-Url: http://git.kpe.io/?p=ctsim.git;a=blobdiff_plain;f=include%2Ffourier.h;h=5215a3a25928ad645869be3c2eeadba9e9b2d875;hp=95aaeb01ed85d02e30ee2a121b9cfe4dd4fd5640;hb=d42d3d062dd1aca92b5a2552a1f474aab0bee610;hpb=8a9896531e2ea87f05a3386015ac9c4334f4db14

diff --git a/include/fourier.h b/include/fourier.h
index 95aaeb0..5215a3a 100644
--- a/include/fourier.h
+++ b/include/fourier.h
@@ -1,45 +1,114 @@
-/*****************************************************************************
-** FILE IDENTIFICATION
-**
-**   Name:          fourier.h
-**   Purpose:       Header for Fourier transform functions
-**   Programmer:    Kevin Rosenberg
-**   Date Started:  Dec 2000
-**
-**  This is part of the CTSim program
-**  Copyright (C) 1983-2001 Kevin Rosenberg
-**
-**  $Id: fourier.h,v 1.1 2001/01/02 06:33:04 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
-**  published by the Free Software Foundation.
-**
-**  This program is distributed in the hope that it will be useful,
-**  but WITHOUT ANY WARRANTY; without even the implied warranty of
-**  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-**  GNU General Public License for more details.
-**
-**  You should have received a copy of the GNU General Public License
-**  along with this program; if not, write to the Free Software
-**  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-******************************************************************************/
-
-#include <complex>
-
-class ImageFile;
-
-class Fourier {
-public:
-    static void shuffleFourierToNaturalOrder (ImageFile& im);
-    static void shuffleNaturalToFourierOrder (ImageFile& im);
-
-    static void shuffleNaturalToFourierOrder (float* pdVector, const int n);
-    static void shuffleNaturalToFourierOrder (double* pdVector, const int n);
-    static void shuffleNaturalToFourierOrder (std::complex<double>* pdVector, const int n);
-    static void shuffleFourierToNaturalOrder (float* pdVector, const int n);
-    static void shuffleFourierToNaturalOrder (double* pdVector, const int n);
-    static void shuffleFourierToNaturalOrder (std::complex<double>* pdVector, const int n);
-
-}; // namespace Fourier
-
+/*****************************************************************************
+** FILE IDENTIFICATION
+**
+**   Name:          fourier.h
+**   Purpose:       Header for Fourier transform functions
+**   Programmer:    Kevin Rosenberg
+**   Date Started:  Dec 2000
+**
+**  This is part of the CTSim program
+**  Copyright (c) 1983-2001 Kevin Rosenberg
+**
+**  $Id$
+**
+**  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
+**  published by the Free Software Foundation.
+**
+**  This program is distributed in the hope that it will be useful,
+**  but WITHOUT ANY WARRANTY; without even the implied warranty of
+**  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+**  GNU General Public License for more details.
+**
+**  You should have received a copy of the GNU General Public License
+**  along with this program; if not, write to the Free Software
+**  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+******************************************************************************/
+
+#include <complex>
+#ifdef HAVE_FFTW
+#include <fftw3.h>
+#endif
+
+class ImageFile;
+
+class Fourier {
+public:
+    static void shuffleFourierToNaturalOrder (ImageFile& im);
+    static void shuffleNaturalToFourierOrder (ImageFile& im);
+
+#ifdef HAVE_FFTW
+    static void shuffleFourierToNaturalOrder (fftw_complex* pc, const int n);
+    static void shuffleNaturalToFourierOrder (fftw_complex* pc, const int n);
+#endif
+    
+// Odd Number of Points
+//   Natural Frequency Order: -(n-1)/2...-1,0,1...(n-1)/2
+//   Fourier Frequency Order: 0, 1..(n-1)/2,-(n-1)/2...-1
+// Even Number of Points
+//   Natural Frequency Order: -n/2...-1,0,1...((n/2)-1)
+//   Fourier Frequency Order: 0,1...((n/2)-1),-n/2...-1
+    template<class T>
+    static void shuffleNaturalToFourierOrder (T* pVector, const int n) 
+    {
+      T* pTemp = new T [n];
+      int i;
+      if (isOdd(n)) { // Odd
+        int iHalfN = (n - 1) / 2;
+
+        pTemp[0] = pVector[iHalfN];
+        for (i = 0; i < iHalfN; i++)
+          pTemp[i + 1] = pVector[i + 1 + iHalfN];
+        for (i = 0; i < iHalfN; i++)
+          pTemp[i + iHalfN + 1] = pVector[i];
+      } else {     // Even
+        int iHalfN = n / 2;
+        pTemp[0] = pVector[iHalfN];
+        for (i = 0; i < iHalfN - 1; i++)
+        pTemp[i + 1] = pVector[i + iHalfN + 1];
+        for (i = 0; i < iHalfN; i++)
+          pTemp[i + iHalfN] = pVector[i];
+      }
+
+    for (i = 0; i < n; i++)
+      pVector[i] = pTemp[i];
+    delete pTemp;
+  }
+
+  template<class T>
+  static void shuffleFourierToNaturalOrder (T* pVector, const int n)
+  {
+    T* pTemp = new T [n];
+    int i;
+    if (isOdd(n)) { // Odd
+      int iHalfN = (n - 1) / 2;
+    
+      pTemp[iHalfN] = pVector[0];
+      for (i = 0; i < iHalfN; i++)
+        pTemp[i + 1 + iHalfN] = pVector[i + 1];
+      for (i = 0; i < iHalfN; i++)
+        pTemp[i] = pVector[i + iHalfN + 1];
+    } else {     // Even
+      int iHalfN = n / 2;
+      pTemp[iHalfN] = pVector[0];
+      for (i = 0; i < iHalfN; i++)
+        pTemp[i] = pVector[i + iHalfN];
+      for (i = 0; i < iHalfN - 1; i++)
+        pTemp[i + iHalfN + 1] = pVector[i+1];
+    }
+  
+    for (i = 0; i < n; i++)
+      pVector[i] = pTemp[i];
+    delete pTemp;
+  }
+#if 0
+    static void shuffleNaturalToFourierOrder (float* pdVector, const int n);
+    static void shuffleNaturalToFourierOrder (double* pdVector, const int n);
+    static void shuffleNaturalToFourierOrder (std::complex<double>* pdVector, const int n);
+    static void shuffleFourierToNaturalOrder (float* pdVector, const int n);
+    static void shuffleFourierToNaturalOrder (double* pdVector, const int n);
+    static void shuffleFourierToNaturalOrder (std::complex<double>* pdVector, const int n);
+#endif
+};
+
+