backend/nsl/nsl_interp.h

0001 /*
0002     File                 : nsl_interp.h
0003     Project              : LabPlot
0004     Description          : NSL interpolation 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_INTERP_H
0011 #define NSL_INTERP_H
0012
0013 #define NSL_INTERP_TYPE_COUNT 11
0014 typedef enum {
0015     nsl_interp_type_linear,
0016     nsl_interp_type_polynomial,
0017     nsl_interp_type_cspline,
0018     nsl_interp_type_cspline_periodic,
0019     nsl_interp_type_akima,
0020     nsl_interp_type_akima_periodic,
0021     nsl_interp_type_steffen,
0022     nsl_interp_type_cosine,
0023     nsl_interp_type_exponential,
0024     nsl_interp_type_pch,
0025     nsl_interp_type_rational
0026 } nsl_interp_type;
0027 extern const char* nsl_interp_type_name[];
0028
0029 #define NSL_INTERP_PCH_VARIANT_COUNT 4
0030 typedef enum {
0031     nsl_interp_pch_variant_finite_difference,
0032     nsl_interp_pch_variant_catmull_rom,
0033     nsl_interp_pch_variant_cardinal,
0034     nsl_interp_pch_variant_kochanek_bartels
0035 } nsl_interp_pch_variant;
0036 extern const char* nsl_interp_pch_variant_name[];
0037
0038 #define NSL_INTERP_EVALUATE_COUNT 4
0039 typedef enum {
0040     nsl_interp_evaluate_function,
0041     nsl_interp_evaluate_derivative,
0042     nsl_interp_evaluate_second_derivative,
0043     nsl_interp_evaluate_integral
0044 } nsl_interp_evaluate;
0045 extern const char* nsl_interp_evaluate_name[];
0046
0047 /* calculates rational interpolation of n points of xy-data at xn using Burlisch-Stoer method. result in v (error dv) */
0048 int nsl_interp_ratint(const double* x, const double* y, int n, double xn, double* v, double* dv);
0049
0050 #endif /* NSL_INTERP_H */