GeopsyCore::DFFTPack Class Reference

Brief description of class still missing. More...

#include <DFFTPack.h>

Inheritance diagram for GeopsyCore::DFFTPack:

List of all members.

Public Member Functions
virtual void	backward (int nSamples, double *samples)
virtual void	backward (int nSamples, Complex *samples)
virtual void	forward (int nSamples, double *samples)
virtual void	forward (int nSamples, Complex *samples)
virtual void	manyBackward (int howmany, int nSamples, Complex *samples)
virtual void	manyForward (int howmany, int nSamples, Complex *samples)

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Detailed Description

Brief description of class still missing.

Full description of class still missing

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Member Function Documentation

void GeopsyCore::DFFTPack::backward	(	int	nSamples,
		double *	samples
	)		[virtual]

Implements GeopsyCore::FastFourierTransform.

References GeopsyCore::DFFTPackCache::begin(), QGpCoreTools::AbstractNumericalCache::end(), GeopsyCore::DFFTPackKey::Real, GeopsyCore::rfftb1_(), and GeopsyCore::DFFTPackCache::wsave().

{
  long n=nSamples;
  double * buf=new double[n];

  // Re-order complex vector
  memcpy(buf, samples, n*sizeof(double));
  // samples[0] is already at the good place
  int i2;
  int n2=n >> 1;
  if(n & 0x00000001) {
    for(int i=n2; i>0; i-- ) {
      i2=i << 1;
      samples[i2-1]=buf[i];
      samples[i2]=buf[n-i];
    }
  } else {
    for(int i=n2-1; i>0; i-- ) {
      i2=i << 1;
      samples[i2-1]=buf[i];
      samples[i2]=buf[n-i];
    }
    samples[n-1]=buf[n2];
  }
  const DFFTPackCache * cache=DFFTPackCache::begin(nSamples, DFFTPackKey::Real);
  rfftb1_(&n, samples, buf, cache->wsave(), cache->wsave()+n);
  DFFTPackCache::end(cache);
  delete [] buf;
}

void GeopsyCore::DFFTPack::backward	(	int	nSamples,
		Complex *	samples
	)		[virtual]

Implements GeopsyCore::FastFourierTransform.

References GeopsyCore::DFFTPackCache::begin(), GeopsyCore::cfftb1_(), GeopsyCore::DFFTPackKey::Complex, QGpCoreTools::AbstractNumericalCache::end(), and GeopsyCore::DFFTPackCache::wsave().

{
  long n=nSamples;
  long n2=n << 1;
  double * buf=new double[n2];

  const DFFTPackCache * cache=DFFTPackCache::begin(nSamples, DFFTPackKey::Complex);
  cfftb1_(&n, samples, buf, cache->wsave(), cache->wsave()+n2);
  DFFTPackCache::end(cache);
  delete [] buf;
}

void GeopsyCore::DFFTPack::forward	(	int	nSamples,
		double *	samples
	)		[virtual]

Output format: r0, r1, r2, ..., r(n+1)/2-1, [, rn/2], i(n+1)/2-1, ..., i2, i1 ([] only for even n)

Uses dfftpack which have a slighly different output format: r0, r1, i1, r2, i2,..., r(n+1)/2-1, i(n+1)/2-1, [rn/2]

Implements GeopsyCore::FastFourierTransform.

References GeopsyCore::DFFTPackCache::begin(), QGpCoreTools::AbstractNumericalCache::end(), GeopsyCore::DFFTPackKey::Real, GeopsyCore::rfftf1_(), and GeopsyCore::DFFTPackCache::wsave().

{
  long n=nSamples;
  double * buf=new double[n];

  const DFFTPackCache * cache=DFFTPackCache::begin(nSamples, DFFTPackKey::Real);
  rfftf1_(&n, samples, buf, cache->wsave(), cache->wsave()+n);
  DFFTPackCache::end(cache);
  // Re-order complex vector
  memcpy(buf, samples, n*sizeof(double));
  // samples[0] is already at the good place
  int i2;
  int n2=n >> 1;
  if(n & 0x00000001) {
    for(int i=n2; i>0; i-- ) {
      i2=i << 1;
      samples[i]=buf[i2-1];
      samples[n-i]=buf[i2];
    }
  } else {
    for(int i=n2-1; i>0; i-- ) {
      i2=i << 1;
      samples[i]=buf[i2-1];
      samples[n-i]=buf[i2];
    }
    samples[n2]=buf[n-1];
  }
  delete [] buf;
}

void GeopsyCore::DFFTPack::forward	(	int	nSamples,
		Complex *	samples
	)		[virtual]

Implements GeopsyCore::FastFourierTransform.

References GeopsyCore::DFFTPackCache::begin(), GeopsyCore::cfftf1_(), GeopsyCore::DFFTPackKey::Complex, QGpCoreTools::AbstractNumericalCache::end(), and GeopsyCore::DFFTPackCache::wsave().

{
  long n=nSamples;
  long n2=n << 1;
  double * buf=new double[n2];

  const DFFTPackCache * cache=DFFTPackCache::begin(nSamples, DFFTPackKey::Complex);
  cfftf1_(&n, samples, buf, cache->wsave(), cache->wsave()+n2);
  DFFTPackCache::end(cache);
  delete [] buf;
}

void GeopsyCore::DFFTPack::manyBackward	(	int	howmany,
		int	nSamples,
		Complex *	samples
	)		[virtual]

Implements GeopsyCore::FastFourierTransform.

References GeopsyCore::DFFTPackCache::begin(), GeopsyCore::cfftb1_(), GeopsyCore::DFFTPackKey::Complex, QGpCoreTools::AbstractNumericalCache::end(), and GeopsyCore::DFFTPackCache::wsave().

{
  long n=nSamples;
  long n2=n << 1;
  double * buf=new double[n2];

  const DFFTPackCache * cache=DFFTPackCache::begin(nSamples, DFFTPackKey::Complex);
  for(int i=0; i<howmany; i++) {
    cfftb1_(&n, samples, buf, cache->wsave(), cache->wsave()+n2);
    samples+=nSamples;
  }
  DFFTPackCache::end(cache);
  delete [] buf;
}

void GeopsyCore::DFFTPack::manyForward	(	int	howmany,
		int	nSamples,
		Complex *	samples
	)		[virtual]

Implements GeopsyCore::FastFourierTransform.

References GeopsyCore::DFFTPackCache::begin(), GeopsyCore::cfftf1_(), GeopsyCore::DFFTPackKey::Complex, QGpCoreTools::AbstractNumericalCache::end(), and GeopsyCore::DFFTPackCache::wsave().

{
  long n=nSamples;
  long n2=n << 1;
  double * buf=new double[n2];

  const DFFTPackCache * cache=DFFTPackCache::begin(nSamples, DFFTPackKey::Complex);
  for(int i=0; i<howmany; i++) {
    cfftf1_(&n, samples, buf, cache->wsave(), cache->wsave()+n2);
    samples+=nSamples;
  }
  DFFTPackCache::end(cache);
  delete [] buf;
}

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The documentation for this class was generated from the following files:

• GeopsyCore/DFFTPack.h
• GeopsyCore/DFFTPack.cpp