/usr/include/purify/kernels.h is in libpurify-dev 2.0.0-2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 | #ifndef PURIFY_KERNELS_H
#define PURIFY_KERNELS_H
#include "purify/config.h"
#include <array>
#include <boost/math/special_functions/bessel.hpp>
#include <boost/math/special_functions/sinc.hpp>
#include "purify/types.h"
namespace purify {
namespace kernels {
//! Kaiser-Bessel kernel
t_real kaiser_bessel(const t_real &x, const t_int &J);
//! More general Kaiser-Bessel kernel
t_real kaiser_bessel_general(const t_real &x, const t_int &J, const t_real &alpha);
//! Fourier transform of more general Kaiser-Bessel kernel
t_real ft_kaiser_bessel_general(const t_real &x, const t_int &J, const t_real &alpha);
//! Fourier transform of kaiser bessel kernel
t_real ft_kaiser_bessel(const t_real &x, const t_int &J);
//! Gaussian kernel
t_real gaussian(const t_real &x, const t_int &J);
//! Fourier transform of Gaussian kernel
t_real ft_gaussian(const t_real &x, const t_int &J);
//! \brief Calculates Horner's Rule the standard PSWF for radio astronomy, with a support of J = 6
//! and alpha = 1.
//! \param[in] eta0: value to evaluate
//! \param[in] J: support size of gridding kernel
//! \param[in] alpha: type of special PSWF to calculate
//! \details The tailored prolate spheroidal wave functions for gridding radio astronomy.
//! Details are explained in Optimal Gridding of Visibility Data in Radio
//! Astronomy, F. R. Schwab 1983.
t_real calc_for_pswf(const t_real &x, const t_int &J, const t_real &alpha);
//! PSWF kernel
t_real pswf(const t_real &x, const t_int &J);
//! Fourier transform of PSWF kernel
t_real ft_pswf(const t_real &x, const t_int &J);
//! Calculates samples of a kernel
Vector<t_real> kernel_samples(const t_int &total_samples,
const std::function<t_real(t_real)> kernelu, const t_int &J);
//! linearly interpolates from samples of kernel
t_real kernel_linear_interp(const Vector<t_real> &samples, const t_real &x, const t_int &J);
//! Box car function for kernel
t_real pill_box(const t_real &x, const t_int &J);
//! Fourier transform of box car function, a Sinc function
t_real ft_pill_box(const t_real &x, const t_int &J);
//! Fourier transform of general Gaussian kernel
t_real gaussian_general(const t_real &x, const t_int &J, const t_real &sigma);
//! Fourier transform of general Gaussian kernel
t_real ft_gaussian_general(const t_real &x, const t_int &J, const t_real &sigma);
}
}
#endif
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