GaussianInterpolator Class Reference

#include <numerical_tools.h>

Public Member Functions
void	initialize (double xmax, int N, bool normalize=true)
double	getValue (double x) const

Detailed Description

Gaussian interpolator

This class helps to perform a quick evaluation of the N(0,1) Gaussian. 1/sqrt(2*PI)*exp(-x^2)

GaussianInterpolator GI;
GI.initialize(6,60000);
double g=GI.getValue(1.96);

Definition at line 104 of file numerical_tools.h.

Member Function Documentation

getValue()

double GaussianInterpolator::getValue ( double  x ) const

inline

Value

Definition at line 118 of file numerical_tools.h.

                                           {
        x=fabs(x);
        if (x>xmax) return 0;
        else
        {
            auto iaux=(int)round(x*ixstep);
            return DIRECT_A1D_ELEM(v,iaux);
        }
    }

initialize()

void GaussianInterpolator::initialize	(	double	xmax,
		int	N,
		bool	normalize = true
	)

Constructor. xmax is the maximum value considered by the interpolator. N is the number of samples between 0 and xmax. If normalize is set to true, then the factor 1/sqrt(2*PI) is introduced.

Definition at line 65 of file numerical_tools.cpp.

{
    xmax=_xmax;
    xstep=xmax/N;
    ixstep=1.0/xstep;
    v.initZeros(N);
    double inorm=1.0/sqrt(2*PI);
    FOR_ALL_ELEMENTS_IN_ARRAY1D(v)
    {
        double x=i*xstep;
        v(i)=exp(-x*x/2);
        if (normalize)
            v(i)*=inorm;
    }
}

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

• xmipp/libraries/data/numerical_tools.h
• xmipp/libraries/data/numerical_tools.cpp