fnft__misc.h

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/*
* This file is part of FNFT.
*
* FNFT is free software; you can redistribute it and/or
* modify it under the terms of the version 2 of the GNU General
* Public License as published by the Free Software Foundation.
*
* FNFT is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Contributors:
* Sander Wahls (TU Delft) 2017-2018.
* Shrinivas Chimmalgi (TU Delft) 2019-2020.
*/
 
#ifndef FNFT__MISC_H
#define FNFT__MISC_H
 
#include "fnft.h"
#include <string.h>
 
void fnft__misc_print_buf(const FNFT_INT len, FNFT_COMPLEX const * const buf,
                          char const * const varname);
 
FNFT_REAL fnft__misc_rel_err(const FNFT_INT len,
    FNFT_COMPLEX const * const vec_numer, FNFT_COMPLEX const * const vec_exact);
 
FNFT_REAL fnft__misc_hausdorff_dist(const FNFT_UINT lenA,
    FNFT_COMPLEX const * const vecA, const FNFT_UINT lenB,
    FNFT_COMPLEX const * const vecB);
 
FNFT_COMPLEX fnft__misc_sech(FNFT_COMPLEX Z);
 
FNFT_REAL fnft__misc_l2norm2(const FNFT_UINT N, FNFT_COMPLEX const * const Z,
    const FNFT_REAL a, const FNFT_REAL b);
 
FNFT_INT fnft__misc_filter(FNFT_UINT * const N, FNFT_COMPLEX * const vals,
    FNFT_COMPLEX * const rearrange_as_well,
    FNFT_REAL const * const bounding_box);
 
 
FNFT_INT fnft__misc_filter_nonreal(FNFT_UINT *N_ptr, FNFT_COMPLEX * const vals,
    const FNFT_REAL tol_im);
 
FNFT_INT fnft__misc_filter_inv(FNFT_UINT * const N_ptr, FNFT_COMPLEX * const vals,
    FNFT_COMPLEX * const rearrange_as_well,
    FNFT_REAL const * const bounding_box);
 
FNFT_INT fnft__misc_merge(FNFT_UINT *N_ptr, FNFT_COMPLEX * const vals,
    FNFT_REAL tol);
 
FNFT_INT fnft__misc_downsample(const FNFT_UINT D, FNFT_COMPLEX const * const q,
    FNFT_UINT * const Dsub_ptr, FNFT_COMPLEX ** qsub_ptr,
    FNFT_UINT * const first_last_index);
 
FNFT_COMPLEX fnft__misc_CSINC(FNFT_COMPLEX x);
 
FNFT_UINT fnft__misc_nextpowerof2(const FNFT_UINT number);
 
FNFT_INT fnft__misc_resample(const FNFT_UINT D, const FNFT_REAL eps_t, FNFT_COMPLEX const * const q,
    const FNFT_REAL delta, FNFT_COMPLEX *const q_new);
 
static inline void fnft__misc_mat_mult_proto(const FNFT_UINT N, FNFT_COMPLEX * const U,
        FNFT_COMPLEX *const T, FNFT_COMPLEX *const TM){
    FNFT_UINT  c1, c2, c3;
    FNFT_COMPLEX sum = 0;
    for (c1 = 0; c1 < N; c1++) {
        for (c2 = 0; c2 < N; c2++) {
            for (c3 = 0; c3 < N; c3++) {
                sum = sum + U[c1*N+c3]*T[c3*N+c2];
            }
            TM[c1*N+c2] = sum;
            sum = 0;
        }
    }
    
    return;
}
 
static inline void fnft__misc_mat_mult_2x2(FNFT_COMPLEX * const U,
        FNFT_COMPLEX *const T){
 
    FNFT_COMPLEX TM[4] = { 0 };
    fnft__misc_mat_mult_proto(2, U, T, &TM[0]);
    memcpy(T,TM,4*sizeof(FNFT_COMPLEX));
    
    return;
}
 
static inline void fnft__misc_mat_mult_4x4(FNFT_COMPLEX * const U,
        FNFT_COMPLEX *const T){
 
    FNFT_COMPLEX TM[16] = { 0 };
    fnft__misc_mat_mult_proto(4, U, T, &TM[0]);
    memcpy(T,TM,16*sizeof(FNFT_COMPLEX));
    
    return;
}
 
static inline FNFT_REAL fnft__misc_legendre_poly(const FNFT_UINT n, const FNFT_REAL x){
    FNFT_UINT  i;
    FNFT_REAL P, P_1, P_2;
    if (n == 0)
        P = 1;
    else if (n == 1)
        P = x;
    else{
        P_1 = x;
        P_2 = 1;
        for (i = 2; i <= n; i++) {
            P = (2.0*i-1)*x*P_1/i -(i-1.0)*P_2/i;
            P_2 = P_1;
            P_1 = P;
        }
    }
    return P;
}
 
#ifdef FNFT_ENABLE_SHORT_NAMES
#define misc_print_buf(...) fnft__misc_print_buf(__VA_ARGS__)
#define misc_rel_err(...) fnft__misc_rel_err(__VA_ARGS__)
#define misc_hausdorff_dist(...) fnft__misc_hausdorff_dist(__VA_ARGS__)
#define misc_sech(...) fnft__misc_sech(__VA_ARGS__)
#define misc_l2norm2(...) fnft__misc_l2norm2(__VA_ARGS__)
#define misc_filter(...) fnft__misc_filter(__VA_ARGS__)
#define misc_filter_inv(...) fnft__misc_filter_inv(__VA_ARGS__)
#define misc_filter_nonreal(...) fnft__misc_filter_nonreal(__VA_ARGS__)
#define misc_merge(...) fnft__misc_merge(__VA_ARGS__)
#define misc_downsample(...) fnft__misc_downsample(__VA_ARGS__)
#define misc_CSINC(...) fnft__misc_CSINC(__VA_ARGS__)
#define misc_nextpowerof2(...) fnft__misc_nextpowerof2(__VA_ARGS__)
#define misc_resample(...) fnft__misc_resample(__VA_ARGS__)
#define misc_mat_mult_proto(...) fnft__misc_mat_mult_proto(__VA_ARGS__)
#define misc_mat_mult_2x2(...) fnft__misc_mat_mult_2x2(__VA_ARGS__)
#define misc_mat_mult_4x4(...) fnft__misc_mat_mult_4x4(__VA_ARGS__)
#define misc_legendre_poly(...) fnft__misc_legendre_poly(__VA_ARGS__)
 
#endif
 
#endif