crosscorr.cpp File Reference

#include "gmxpre.h"
#include "crosscorr.h"
#include "gromacs/fft/fft.h"
#include "gromacs/utility/exceptions.h"
#include "gromacs/utility/smalloc.h"

Include dependency graph for crosscorr.cpp:

Description

Implements routine for computing a cross correlation between two data sets.

Author

David van der Spoel david.nosp@m..van.nosp@m.dersp.nosp@m.oel@.nosp@m.icm.u.nosp@m.u.se

Functions
static int	zeroPaddingSize (int n)
	return the size witch the array should be after zero padding More...
static void	complexConjugatMult (t_complex *in1, t_complex *in2)
	Compute complex conjugate. Output in the first input variable. More...
static void	cross_corr_low (int n, const real f[], const real g[], real corr[], gmx_fft_t fft)
	Compute one cross correlation corr = f x g using FFT. More...
void	cross_corr (int n, real f[], real g[], real corr[])
	fft cross correlation algorithm. Computes corr = f (.) g More...
void	many_cross_corr (int nFunc, int *nData, real **f, real **g, real **corr)
	fft cross correlation algorithm. More...

Function Documentation

static void complexConjugatMult ( t_complex *  in1, t_complex *  in2  )

static

Compute complex conjugate. Output in the first input variable.

Parameters

[in]	in1	first complex number
[in]	in2	second complex number

void cross_corr	(	int	n,
		real	f[],
		real	g[],
		real	corr[]
	)

fft cross correlation algorithm. Computes corr = f (.) g

Parameters

[in]	n	number of data point
[in]	f	First function
[in]	g	Second function
[out]	corr	The cross correlation

static void cross_corr_low ( int  n, const real  f[], const real  g[], real  corr[], gmx_fft_t  fft  )

static

Compute one cross correlation corr = f x g using FFT.

Parameters

[in]	n	number of data point
[in]	f	first function
[in]	g	second function
[out]	corr	output correlation
[in]	fft	FFT data structure

void many_cross_corr	(	int	nFunc,
		int *	nData,
		real **	f,
		real **	g,
		real **	corr
	)

fft cross correlation algorithm.

Computes corr[n] = f[n]i g[n][i], that is for nFunc pairs of arrays n the cross correlation is computed in parallel using OpenMP.

Parameters

[in]	nFunc	nuber of function to crosscorrelate
[in]	nData	number of data point in eatch function
[in]	f	2D array of first function to crosscorrelate
[in]	g	2D array of second function to crosscorrelate
[out]	corr	2D array of the cross correlations

static int zeroPaddingSize ( int  n )

static

return the size witch the array should be after zero padding

Parameters

[in]

n

Factor to multiply by 2

Returns

zeroPaddingSize