File indexing completed on 2024-05-12 03:47:50
0001 /* 0002 File : nsl_diff.h 0003 Project : LabPlot 0004 Description : NSL numerical differentiation functions 0005 -------------------------------------------------------------------- 0006 SPDX-FileCopyrightText: 2016 Stefan Gerlach <stefan.gerlach@uni.kn> 0007 SPDX-License-Identifier: GPL-2.0-or-later 0008 */ 0009 0010 #ifndef NSL_DIFF_H 0011 #define NSL_DIFF_H 0012 0013 #include <stdlib.h> 0014 0015 #define NSL_DIFF_DERIV_ORDER_COUNT 6 0016 typedef enum { 0017 nsl_diff_deriv_order_first, 0018 nsl_diff_deriv_order_second, 0019 nsl_diff_deriv_order_third, 0020 nsl_diff_deriv_order_fourth, 0021 nsl_diff_deriv_order_fifth, 0022 nsl_diff_deriv_order_sixth 0023 } nsl_diff_deriv_order_type; 0024 extern const char* nsl_diff_deriv_order_name[]; 0025 0026 /************ finite differences *********/ 0027 0028 /* first derivative, central 0029 remark: do we need this? 0030 */ 0031 double nsl_diff_first_central(double xm, double fm, double xp, double fp); 0032 0033 /************ first derivatives *********/ 0034 0035 /* calculates derivative of n points of xy-data. 0036 for equal/unequal spaced data. 0037 result in y 0038 */ 0039 int nsl_diff_first_deriv_equal(const double* x, double* y, const size_t n); 0040 int nsl_diff_first_deriv(const double* x, double* y, const size_t n, int order); 0041 int nsl_diff_first_deriv_second_order(const double* x, double* y, const size_t n); 0042 int nsl_diff_first_deriv_fourth_order(const double* x, double* y, const size_t n); 0043 /* using average between left and right diff (like in other programs) */ 0044 int nsl_diff_first_deriv_avg(const double* x, double* y, const size_t n); 0045 0046 /************ second derivatives *********/ 0047 0048 /* calculates second derivative of n points of xy-data 0049 for unequal spaced data. 0050 result in y 0051 */ 0052 int nsl_diff_second_deriv(const double* x, double* y, const size_t n, int order); 0053 int nsl_diff_second_deriv_first_order(const double* x, double* y, const size_t n); 0054 int nsl_diff_second_deriv_second_order(const double* x, double* y, const size_t n); 0055 int nsl_diff_second_deriv_third_order(const double* x, double* y, const size_t n); 0056 0057 /************ third derivatives *********/ 0058 0059 /* calculates third derivative of n points of xy-data 0060 for unequal spaced data. 0061 result in y 0062 */ 0063 int nsl_diff_third_deriv(const double* x, double* y, const size_t n, int order); 0064 int nsl_diff_third_deriv_second_order(const double* x, double* y, const size_t n); 0065 0066 /************ fourth derivatives *********/ 0067 0068 /* calculates fourth derivative of n points of xy-data 0069 for unequal spaced data. 0070 result in y 0071 */ 0072 int nsl_diff_fourth_deriv(const double* x, double* y, const size_t n, int order); 0073 int nsl_diff_fourth_deriv_first_order(const double* x, double* y, const size_t n); 0074 int nsl_diff_fourth_deriv_third_order(const double* x, double* y, const size_t n); 0075 0076 /************ fifth derivatives *********/ 0077 0078 /* calculates fifth derivative of n points of xy-data 0079 for unequal spaced data. 0080 result in y 0081 */ 0082 int nsl_diff_fifth_deriv(const double* x, double* y, const size_t n, int order); 0083 int nsl_diff_fifth_deriv_second_order(const double* x, double* y, const size_t n); 0084 0085 /************ sixth derivatives *********/ 0086 0087 /* calculates sixth derivative of n points of xy-data 0088 for unequal spaced data. 0089 result in y 0090 */ 0091 int nsl_diff_sixth_deriv(const double* x, double* y, const size_t n, int order); 0092 int nsl_diff_sixth_deriv_first_order(const double* x, double* y, const size_t n); 0093 0094 #endif /* NSL_DIFF_H */