dft.h

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/* Copyright (C) 2015-2017 Chris Piker <chris-piker@uiowa.edu>
 *
 * This file is part of libdas2, the Core Das2 C Library.
 * 
 * Libdas2 is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License version 2.1 as published
 * by the Free Software Foundation.
 *
 * Libdas2 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 Lesser General Public License for
 * more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 2.1 along with libdas2; if not, see <http://www.gnu.org/licenses/>. 
 */


#ifndef _das_dft_h_
#define _das_dft_h_
       
#ifdef __cplusplus
extern "C" {
#endif


/* Called from das_init */
bool dft_init(const char* sProgName);

typedef struct dft_plan DftPlan;

DftPlan* new_DftPlan(size_t uLen, bool bForward);


bool del_DftPlan(DftPlan* pThis);

typedef struct das_dft_t{
   
   /* The plan, the only varible changed in the plan is the usage count */
   DftPlan* pPlan;

   /* FFTW variables */
   void* vpIn;
   void* vpOut;
   
   /* Input vector length */
   size_t uLen;
   
   /* Input vector is real only*/
   bool bRealOnly;
   
   /* DFT Direction */
   bool bForward;
   
   /* Holder for the window function and name*/
   char* sWindow;
   double* pWnd;
   
   /* Holder for the magnitude result */
   bool bNewMag;
   double* pMag;
   size_t uMagLen;
   
   /* Holder for continuous real and imaginary results */
   bool bNewCmp[2];   /* fftw convention: 0 = reals, 1 = img */
   double* pCmpOut[2];
   size_t uCmpLen[2];
   
} Das2Dft;

Das2Dft* new_Dft(DftPlan* pPlan, const char* sWindow);

void del_Dft(Das2Dft* pThis);

DasErrCode Dft_calculate(
   Das2Dft* pThis, const double* pReal, const double* pImg
);

const double* Dft_getReal(Das2Dft* pThis, size_t* pLen);

const double* Dft_getImg(Das2Dft* pThis, size_t* pLen);

const double* Dft_getMagnitude(Das2Dft* pThis, size_t* pLen);

typedef struct das_psd_t{
   
   /* The plan, the only varible changed in the plan is the usage count */
   DftPlan* pPlan;
   
   /* FFTW variables */
   void* vpIn;
   void* vpOut;
   
   /* Input vector information */
   size_t uLen;
   bool bRealOnly;
   
   /* Center data about average first */
   bool bCenter;
   
   /* Holder for up conversion arrays, helps Psd_calculate_f*/
   size_t uUpConvLen;
   double* pUpConvReal;
   double* pUpConvImg;
   
   /* Holder for the window function and name */
   char* sWindow;
   double* pWnd;
   double rWndSqSum;
   
   /* Holder for the PSD result */
   double* pMag;
   size_t uMagLen;
   
   /* Total Energy calculations */
   double rPwrIn;
   double rPwrOut;
   
} Das2Psd;

Das2Psd* new_Psd(DftPlan* pPlan,  bool bCenter, const char* sWindow);

void del_Das2Psd(Das2Psd* pThis);


DasErrCode Psd_calculate(
   Das2Psd* pThis, const double* pReal, const double* pImg
);

DasErrCode Psd_calculate_f(
   Das2Psd* pThis, const float* pReal, const float* pImg
);

double Psd_powerRatio(const Das2Psd* pThis, double* pInput, double* pOutput);


const double* Psd_get(const Das2Psd* pThis, size_t* pLen);

#ifdef __cplusplus
}
#endif

#endif