vector_handler.hpp

#ifndef VECTOR_HANDLER_CLASS_HPP
#define VECTOR_HANDLER_CLASS_HPP

#include <fftw3.h>
#include <math.h>
#include <stdio.h>

class VectorHandler{
    int dim;
    double dimCoeff;

public:
    /* multiply two vectors componentwise and save result in the third
     * one */
    static void multiplyVecs(const double *f, const double *g, double *fg,
        int size);

    /* multiply square matrix and vector: b = A * x */
    static void multiplyMatVec(double *A, double *x, double *b, int n);

    /* shift vector left (not rolling) */
    static void shiftLeft(double *f, int size, int shft);

    /* copies vector to another storage */
    static void copy(double *dst, const double *src, int count);

    /* store vector into the file as list of pair 'x f(x)' */
    static void storeVector(const double *f, const char *path, int size,
        double step, double origin, int accurancy);

    static double weight(int i, int n, double step)
    {
        return i == 0 || i == n - 1 ? step / 2 : step;
    }

    VectorHandler() : dim(1) { dimCoeff = 2.0; }
    VectorHandler(int dim) : dim(dim)
    {
        dimCoeff = dim == 1 ? 2.0 : dim == 2 ? 2.0 * M_PI : 4.0 * M_PI;
    }

    const int getDimension() const { return dim; }

    /* get integral dot product */
    double getDot(const double *f, const double *g, int size, double step,
        double origin) const;

    /* return integral norm of vecor */
    double getIntNorm(const double *f, int size, double step,
        double origin) const;

    /* return dispersion of vector using it as probability density */
    double getDispersion(const double *f, int size, double step,
        double origin) const;

    /* return kurtosis of vector using it as probability density,
     * with expected value equals 0
     */
    double getKurtosis(const double *f, int size, double step,
        double origin) const;


private:
    /* TODO: make jacobian more logical and faster */
    double jacobian(double x) const
    {
        return
            dim == 1 ? 1.0 :
            dim == 2 ? x :
                       x * x;
    }
};

#endif