eg_dmatrix.ex.c File Reference

Detailed Description

This file shows some examples of the use of EGdMatrix_t structure and functions. as a test-set we use the Hilber Matrix wich is a matrix with coefficients $H^n_{i,j} = \frac1{i+j-1}$ . It is well known that the Hilbert matrix is extremmaly ill conditioned, and is very hard to invert, here are some values for it's determinant for different dimmensions $n$

$\mathrm{det}(H_1) = 1$ .
$\mathrm{det}(H_2) = \frac1{12}$ .
$\mathrm{det}(H_3) = \frac1{2160}$ .
$\mathrm{det}(H_4) = \frac1{604800}$ .
$\mathrm{det}(H_5) = \frac1{266716800000}$ . Since a lot is known about the Hilber Matrix, some accuracy tests are possible. For more details see MathWorld This test program takes as input the number of columns and rows for the hilbert matrix, and so some operations on it and display it to the standard output.

Definition in file eg_dmatrix.ex.c.

#include <stdio.h>
#include <stdlib.h>
#include <inttypes.h>
#include "eg_dmatrix.h"
#include "eg_dbasis_red.h"

Include dependency graph for eg_dmatrix.ex.c:

Go to the source code of this file.

Defines

#define HILBERT_TABLE_SIZE 9U

size of the table of eigenvalues of the hilbert matrix

Functions

int dmatrix_parseargs (int argc, char **argv, size_t *n, size_t *m)

parse the input argumenbts for the program

void dmatrix_usage (char *program)

display the usage message for this program

int main (int argc, char **argv)

main function

Variables

static unsigned dmatrix_hilbert_eigenvalues [HILBERT_TABLE_SIZE]

table containing 1/eigenvalues of the hilbert matrix.

Generated on Mon Jan 30 08:50:40 2006 for EGlib by

1.4.5


Defines
#define	HILBERT_TABLE_SIZE 9U
	size of the table of eigenvalues of the hilbert matrix
Functions
int	dmatrix_parseargs (int argc, char *argv, size_t n, size_t *m)
	parse the input argumenbts for the program
void	dmatrix_usage (char *program)
	display the usage message for this program
int	main (int argc, char **argv)
	main function
Variables
static unsigned	dmatrix_hilbert_eigenvalues [HILBERT_TABLE_SIZE]
	table containing 1/eigenvalues of the hilbert matrix.