/* specfunc/gsl_sf_legendre.h * * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2004 Gerard Jungman * Copyright (C) 2019 Patrick Alken * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or (at * your option) any later version. * * This program 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, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ /* Author: G. Jungman */ #ifndef __GSL_SF_LEGENDRE_H__ #define __GSL_SF_LEGENDRE_H__ #include #include #include #undef __BEGIN_DECLS #undef __END_DECLS #ifdef __cplusplus # define __BEGIN_DECLS extern "C" { # define __END_DECLS } #else # define __BEGIN_DECLS /* empty */ # define __END_DECLS /* empty */ #endif __BEGIN_DECLS /* P_l(x) l >= 0; |x| <= 1 * * exceptions: GSL_EDOM */ int gsl_sf_legendre_Pl_e(const int l, const double x, gsl_sf_result * result); double gsl_sf_legendre_Pl(const int l, const double x); /* P_l(x) for l=0,...,lmax; |x| <= 1 * * exceptions: GSL_EDOM */ int gsl_sf_legendre_Pl_array( const int lmax, const double x, double * result_array ); /* P_l(x) and P_l'(x) for l=0,...,lmax; |x| <= 1 * * exceptions: GSL_EDOM */ int gsl_sf_legendre_Pl_deriv_array( const int lmax, const double x, double * result_array, double * result_deriv_array ); /* P_l(x), l=1,2,3 * * exceptions: none */ int gsl_sf_legendre_P1_e(double x, gsl_sf_result * result); int gsl_sf_legendre_P2_e(double x, gsl_sf_result * result); int gsl_sf_legendre_P3_e(double x, gsl_sf_result * result); double gsl_sf_legendre_P1(const double x); double gsl_sf_legendre_P2(const double x); double gsl_sf_legendre_P3(const double x); /* Q_0(x), x > -1, x != 1 * * exceptions: GSL_EDOM */ int gsl_sf_legendre_Q0_e(const double x, gsl_sf_result * result); double gsl_sf_legendre_Q0(const double x); /* Q_1(x), x > -1, x != 1 * * exceptions: GSL_EDOM */ int gsl_sf_legendre_Q1_e(const double x, gsl_sf_result * result); double gsl_sf_legendre_Q1(const double x); /* Q_l(x), x > -1, x != 1, l >= 0 * * exceptions: GSL_EDOM */ int gsl_sf_legendre_Ql_e(const int l, const double x, gsl_sf_result * result); double gsl_sf_legendre_Ql(const int l, const double x); /* P_l^m(x) m >= 0; l >= m; |x| <= 1.0 * * Note that this function grows combinatorially with l. * Therefore we can easily generate an overflow for l larger * than about 150. * * There is no trouble for small m, but when m and l are both large, * then there will be trouble. Rather than allow overflows, these * functions refuse to calculate when they can sense that l and m are * too big. * * If you really want to calculate a spherical harmonic, then DO NOT * use this. Instead use legendre_sphPlm() below, which uses a similar * recursion, but with the normalized functions. * * exceptions: GSL_EDOM, GSL_EOVRFLW */ int gsl_sf_legendre_Plm_e(const int l, const int m, const double x, gsl_sf_result * result); double gsl_sf_legendre_Plm(const int l, const int m, const double x); /* P_l^m(x) m >= 0; l >= m; |x| <= 1.0 * l=|m|,...,lmax * * exceptions: GSL_EDOM, GSL_EOVRFLW */ int gsl_sf_legendre_Plm_array( const int lmax, const int m, const double x, double * result_array ); /* P_l^m(x) and d(P_l^m(x))/dx; m >= 0; lmax >= m; |x| <= 1.0 * l=|m|,...,lmax * * exceptions: GSL_EDOM, GSL_EOVRFLW */ int gsl_sf_legendre_Plm_deriv_array( const int lmax, const int m, const double x, double * result_array, double * result_deriv_array ); /* P_l^m(x), normalized properly for use in spherical harmonics * m >= 0; l >= m; |x| <= 1.0 * * There is no overflow problem, as there is for the * standard normalization of P_l^m(x). * * Specifically, it returns: * * sqrt((2l+1)/(4pi)) sqrt((l-m)!/(l+m)!) P_l^m(x) * * exceptions: GSL_EDOM */ int gsl_sf_legendre_sphPlm_e(const int l, int m, const double x, gsl_sf_result * result); double gsl_sf_legendre_sphPlm(const int l, const int m, const double x); /* sphPlm(l,m,x) values * m >= 0; l >= m; |x| <= 1.0 * l=|m|,...,lmax * * exceptions: GSL_EDOM */ int gsl_sf_legendre_sphPlm_array( const int lmax, int m, const double x, double * result_array ); /* sphPlm(l,m,x) and d(sphPlm(l,m,x))/dx values * m >= 0; l >= m; |x| <= 1.0 * l=|m|,...,lmax * * exceptions: GSL_EDOM */ int gsl_sf_legendre_sphPlm_deriv_array( const int lmax, const int m, const double x, double * result_array, double * result_deriv_array ); /* size of result_array[] needed for the array versions of Plm * (lmax - m + 1) */ int gsl_sf_legendre_array_size(const int lmax, const int m); /* Irregular Spherical Conical Function * P^{1/2}_{-1/2 + I lambda}(x) * * x > -1.0 * exceptions: GSL_EDOM */ int gsl_sf_conicalP_half_e(const double lambda, const double x, gsl_sf_result * result); double gsl_sf_conicalP_half(const double lambda, const double x); /* Regular Spherical Conical Function * P^{-1/2}_{-1/2 + I lambda}(x) * * x > -1.0 * exceptions: GSL_EDOM */ int gsl_sf_conicalP_mhalf_e(const double lambda, const double x, gsl_sf_result * result); double gsl_sf_conicalP_mhalf(const double lambda, const double x); /* Conical Function * P^{0}_{-1/2 + I lambda}(x) * * x > -1.0 * exceptions: GSL_EDOM */ int gsl_sf_conicalP_0_e(const double lambda, const double x, gsl_sf_result * result); double gsl_sf_conicalP_0(const double lambda, const double x); /* Conical Function * P^{1}_{-1/2 + I lambda}(x) * * x > -1.0 * exceptions: GSL_EDOM */ int gsl_sf_conicalP_1_e(const double lambda, const double x, gsl_sf_result * result); double gsl_sf_conicalP_1(const double lambda, const double x); /* Regular Spherical Conical Function * P^{-1/2-l}_{-1/2 + I lambda}(x) * * x > -1.0, l >= -1 * exceptions: GSL_EDOM */ int gsl_sf_conicalP_sph_reg_e(const int l, const double lambda, const double x, gsl_sf_result * result); double gsl_sf_conicalP_sph_reg(const int l, const double lambda, const double x); /* Regular Cylindrical Conical Function * P^{-m}_{-1/2 + I lambda}(x) * * x > -1.0, m >= -1 * exceptions: GSL_EDOM */ int gsl_sf_conicalP_cyl_reg_e(const int m, const double lambda, const double x, gsl_sf_result * result); double gsl_sf_conicalP_cyl_reg(const int m, const double lambda, const double x); /* The following spherical functions are specializations * of Legendre functions which give the regular eigenfunctions * of the Laplacian on a 3-dimensional hyperbolic space. * Of particular interest is the flat limit, which is * Flat-Lim := {lambda->Inf, eta->0, lambda*eta fixed}. */ /* Zeroth radial eigenfunction of the Laplacian on the * 3-dimensional hyperbolic space. * * legendre_H3d_0(lambda,eta) := sin(lambda*eta)/(lambda*sinh(eta)) * * Normalization: * Flat-Lim legendre_H3d_0(lambda,eta) = j_0(lambda*eta) * * eta >= 0.0 * exceptions: GSL_EDOM */ int gsl_sf_legendre_H3d_0_e(const double lambda, const double eta, gsl_sf_result * result); double gsl_sf_legendre_H3d_0(const double lambda, const double eta); /* First radial eigenfunction of the Laplacian on the * 3-dimensional hyperbolic space. * * legendre_H3d_1(lambda,eta) := * 1/sqrt(lambda^2 + 1) sin(lam eta)/(lam sinh(eta)) * (coth(eta) - lambda cot(lambda*eta)) * * Normalization: * Flat-Lim legendre_H3d_1(lambda,eta) = j_1(lambda*eta) * * eta >= 0.0 * exceptions: GSL_EDOM */ int gsl_sf_legendre_H3d_1_e(const double lambda, const double eta, gsl_sf_result * result); double gsl_sf_legendre_H3d_1(const double lambda, const double eta); /* l'th radial eigenfunction of the Laplacian on the * 3-dimensional hyperbolic space. * * Normalization: * Flat-Lim legendre_H3d_l(l,lambda,eta) = j_l(lambda*eta) * * eta >= 0.0, l >= 0 * exceptions: GSL_EDOM */ int gsl_sf_legendre_H3d_e(const int l, const double lambda, const double eta, gsl_sf_result * result); double gsl_sf_legendre_H3d(const int l, const double lambda, const double eta); /* Array of H3d(ell), 0 <= ell <= lmax */ int gsl_sf_legendre_H3d_array(const int lmax, const double lambda, const double eta, double * result_array); /* associated legendre P_{lm} routines */ typedef enum { GSL_SF_LEGENDRE_SCHMIDT, GSL_SF_LEGENDRE_SPHARM, GSL_SF_LEGENDRE_FULL, GSL_SF_LEGENDRE_NONE } gsl_sf_legendre_t; int gsl_sf_legendre_array(const gsl_sf_legendre_t norm, const size_t lmax, const double x, double result_array[]); int gsl_sf_legendre_array_e(const gsl_sf_legendre_t norm, const size_t lmax, const double x, const double csphase, double result_array[]); int gsl_sf_legendre_deriv_array(const gsl_sf_legendre_t norm, const size_t lmax, const double x, double result_array[], double result_deriv_array[]); int gsl_sf_legendre_deriv_array_e(const gsl_sf_legendre_t norm, const size_t lmax, const double x, const double csphase, double result_array[], double result_deriv_array[]); int gsl_sf_legendre_deriv_alt_array(const gsl_sf_legendre_t norm, const size_t lmax, const double x, double result_array[], double result_deriv_array[]); int gsl_sf_legendre_deriv_alt_array_e(const gsl_sf_legendre_t norm, const size_t lmax, const double x, const double csphase, double result_array[], double result_deriv_array[]); int gsl_sf_legendre_deriv2_array(const gsl_sf_legendre_t norm, const size_t lmax, const double x, double result_array[], double result_deriv_array[], double result_deriv2_array[]); int gsl_sf_legendre_deriv2_array_e(const gsl_sf_legendre_t norm, const size_t lmax, const double x, const double csphase, double result_array[], double result_deriv_array[], double result_deriv2_array[]); int gsl_sf_legendre_deriv2_alt_array(const gsl_sf_legendre_t norm, const size_t lmax, const double x, double result_array[], double result_deriv_array[], double result_deriv2_array[]); int gsl_sf_legendre_deriv2_alt_array_e(const gsl_sf_legendre_t norm, const size_t lmax, const double x, const double csphase, double result_array[], double result_deriv_array[], double result_deriv2_array[]); size_t gsl_sf_legendre_array_n(const size_t lmax); size_t gsl_sf_legendre_nlm(const size_t lmax); INLINE_DECL size_t gsl_sf_legendre_array_index(const size_t l, const size_t m); #ifdef HAVE_INLINE /* gsl_sf_legendre_array_index() This routine computes the index into a result_array[] corresponding to a given (l,m) */ INLINE_FUN size_t gsl_sf_legendre_array_index(const size_t l, const size_t m) { return (((l * (l + 1)) >> 1) + m); } #endif /* HAVE_INLINE */ __END_DECLS #endif /* __GSL_SF_LEGENDRE_H__ */