58 lines
2.1 KiB
C
58 lines
2.1 KiB
C
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// Authors: Unknown. Please, if you are the author of this file, or if you
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// know who are the authors of this file, let us know, so we can give the
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// adequate credits and/or get the adequate authorizations.
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#ifndef _NUMERICS_H_
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#define _NUMERICS_H_
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#include <stdio.h>
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#include <stdlib.h>
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#include <math.h>
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#include <fstream>
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#include <iostream>
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#include "library.h"
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#define NRMAX(i,j) ( (i)<(j) ? (j):(i) )
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#define NRMIN(i,j) ( (i)<(j) ? (i):(j) )
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#define NRTINY 1.0e-10
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// **********************************************
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// float ** basic functions
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// **********************************************
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float ** allocate_float_matrix(int nrows, int ncols);
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void desallocate_float_matrix(float **matrix, int nrows, int ncols);
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// **********************************************
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// LU based algorithms
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// **********************************************
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// Solves Ax=b by using lu decomposition
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// a matrix a[1..n][1..n] is replaced by the LU decompositions of a rowwise permutation of itself
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// b[1..n] and x[1..n]
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int lusolve(float **a, float *x, float *b, int n);
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/*-- LU decomposition */
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/* Given a matrix a[1..n][1..n] this routine replacess it by the LU decompositions of a rowwise permutation of itself. */
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/* a and n are input, a is output, arranged as in equation (2.3.14) above; indx[1..n] in an output vector that records */
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/* the row permutation effected by the partial pivoting; d is output as +-1 depending on whether the number of row */
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/* interchanges was even or odd respectively. */
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int ludcmp(float **a, int n, int *indx, float *d); /* LU decomposition */
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/* Solves the set of n linear equations Ax=b. Here a[0..n-1][0..n-1] as input, not as the matrix A but rather as its LU decomposition,*/
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/* determined by the routine ludcmp. indx[0..n-1] is input as the permutation vector returned by ludcmp. b[0..n-1] is input as the */
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/* right hand side vector and returns with the solution vector x. */
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void lubksb(float **a, int n, int *indx, float *b); /* LU linear solution */
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#endif
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