/* * cepInterp.h * * Description:- Interpolation toolkit. Provides various methods of * interpolation. * * Copyright (C) Nick Wheatstone 2002 * * 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 2 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., 675 * Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include #include #include "cepMatrix.h" #include "cepError.h" #include "cepDate.h" #ifndef __CEP_INTERP_H #define __CEP_INTERP_H const int NEAREST_INTERP = 1; const int LINEAR_INTERP = 2; const int NATURAL_SPLINE_INTERP = 3; const int CUBIC_SPLINE_INTERP = 4; const int DIVIDED_INTERP = 5; /**** DOCBOOK START cep Interpolation class This class has been designed for the purpose of interpolating geodesy data matrices to new timescales. The forseen use of this class is to simulate datasets with a standard sanpling rate. To this end the class has 2 use methods, both called do interp. One where you provide a sample rate and a second where a custom timescale may be provided. DOCBOOK END ****/ class cepInterp { public: cepInterp (); /******* doInterp method 1: Interpolates data to a set sample rate cepMatrix & doInterp(const cepMatrix & input, double sampleRate, int interpType, int winSize = 1, double winOverlap = 0); Imports: input: Is a single window matrix, with date as the first row and location values as the second row. sampleRate: The sample rate that the data is going to be interpolated to in decimal years. interpType: Type of interpolation to be used: NEAREST_INTERP: (1) Nearest neigbour interpolation LINEAR_INTERP: (2) Linear interpolation between points NATURAL_SPLINE_INTERP: (3) Natural spline interpolation CUBIC_SPLINE_INTERP: (4) p spline interpolation DIVIDED_INTERP: (5) newton divided differences winSize(optional): Used for getting datasets that divide into complete windows. Data value is the length of the window in number of samples. winOverlap(optional): Used for getting complete windows. Data value is the proportion of overlap between windows. This is to be given as a number: 0.0 <= winOverlap < 1.0. Export: return value: Interpolated cepMatrix. DOCBOOK END */ cepMatrix < double >doInterp (cepMatrix < double >&input, double sampleRate, int interpType, int winSize = 1, double winOverlap = 0.0); /**** DOCBOOK START doInterp method 2: Interpolates data to a new timescale cepMatrix & doInterp(const cepMatrix & input, cepMatrix & timeScale, int interpType); Imports: input: Is a single window matrix, with date as the first column and location values as the second column. timescale: 2 column matrix where the first column defines a new timescale and the second column is blank. Note: This value is changed (can also be used as a return value) interpType: Type of interpolation to be used: NEAREST_INTERP: (1) Nearest neigbour interpolation LINEAR_INTERP: (2) Linear interpolation between points NATURAL_SPLINE_INTERP: (3) Natural spline interpolation CUBIC_SPLINE_INTERP: (4) p spline interpolation DIVIDED_INTERP: (5) newton divided differences Exports: return value: 2 column matrix where the first column is the timescale and the second column is the interpolated data points to fit that timescale DOCBOOK END */ cepMatrix < double >doInterp (cepMatrix < double >&input, cepMatrix < double >&timeScale, int interpType); cepMatrix < double >LSinterp (cepMatrix < double >&input, double sampleRate, double m, double c); private: double delta; // Member variable for catching errors cepError m_error; // internal interpolation implementation methods /* Basic usage for ALL internal interpolation classes: Imports: input: Is a single window matrix, with date as the first column and location values as the second column. timescale: 2 column matrix where the first column defines a new timescale and the second column is blank. Note: This value is changed (can also be used as a return value) Exports: return value: 2 column matrix where the first column is the timescale and the second column is the interpolated data points to fit that timescale */ // Nearest neighbour interpolation // Estimates points to be equal to nearest point cepMatrix < double >nearestInterp (cepMatrix < double >&input, cepMatrix < double >&timeScale); // Linear interpolation // Estimates new points as a linear interp of the 2 nearest points cepMatrix < double >linearInterp (cepMatrix < double >&input, cepMatrix < double >&timeScale); // Natural spline interpolation // Estimates new points using a natural spline // (Natural spline: second derivatives of end points = 0) cepMatrix < double >naturalSplineInterp (cepMatrix < double >&input, cepMatrix < double >&timeScale); // Cubic spline interpolation // Estimates new points using a P spline // (P spline: second derivative of end points = second to end points) cepMatrix < double >cubicSplineInterp (cepMatrix < double >&input, cepMatrix < double >&timeScale); // Divided difference interpolation // Estimates new points using newton divided differences // (order of divided differences optimized for minimum error) cepMatrix < double >dividedInterp (cepMatrix < double >&input, cepMatrix < double >&timeScale); // Used for keeping fill command within bounds while interpolation // (also icrements counter) bool inBounds (cepMatrix < double >&input, cepMatrix < double >&timeScale, int &position, int &i, int newSize, int oldSize); // RowReduce: (used in spline interpolation) // Row reduces a tridiagonal matrix t augmented by the middle n-1 rows of s // to save memory t is stored as a 3 by n-1 matrix void rowReduce (cepMatrix < double >&t, cepMatrix < double >&s, int n); // calc_abc: (used in spline interpolation) // Calculates the the a, b and c parameter of a spline model (see spline documentation) // Imports: s, h, import, n // Exports: a, b, c void calc_abc (cepMatrix < double >&a, cepMatrix < double >&b, cepMatrix < double >&c, cepMatrix < double >&s, cepMatrix < double >&h, cepMatrix < double >&input, int n); // setColour: (used to set different colours to new points) // Used at generation time of an interpolated matrix // Imports: input (original matrix) // timeScale (interped matrix to be coloured) // position (current position in input) // i (current position in timeScale) void setColour (cepMatrix < double >&input, cepMatrix < double >&timeScale, int position, int i); }; #endif // ! __CEP_INTERP_H