#include "genocop.h"/********************************************************************************//*                                                                              *//*           FUNCTION NAME     :   inverse()                                    *//*                                                                              *//*           SYNOPSIS          :   void inverse(a,a_inverse,n)                  *//*                                                                              *//*           DESCRIPTION       :   This function finds the inverse matrix of a  *//*                                  given float matrix                          *//*                                                                              *//*           FUNCTIONS CALLED  :   det(),                                       *//*                                 matrix().                                    *//*                                                                              *//*           CALLING FUNCITONS :   main()                                       *//*                                                                              *//*           AUTHOR            :   Swarnalatha Swaminathan                      *//*                                                                              *//*           DATE              :   1/17/92                                      *//*                                                                              *//*                                                                              *//*           REV            DATE            BY           DESCRIPTION            *//*           ---            ----            --           -----------            *//*                                                                              *//*                                                                              *//********************************************************************************/void inverse(a, a_inverse, n)    MATRIX          a, a_inverse;	    /* the original and the inverse					     * matrices */    int             n;			    /* the dimension of the matrix */{    int             i, j, k, k1, l, l1, n1; /* counter variables */    float           d1,			    /* determinat of the matrix */                    v, w;    MATRIX          b;			    /* a temporary float matrix */    b = matrix(1, n, 1, n);    for (i = 1; i <= n; i++)	for (j = 1; j <= n; j++)	    b[i][j] = 0.0;    d1 = det(a, n);    if (d1 == 0.0)    {	printf("Variables are dependant : No inverse exists.\n\n");	exit(1);    } else    {	v = -1.0;	for (i = 1; i <= n; i++)	{	    v = -v;	    w = -1.0;	    for (j = 1; j <= n; j++)	    {		w = -w;		n1 = n - 1;		for (k = 1; k <= n1; k++)		{		    k1 = k;		    if (k >= i)			k1 = k + 1;		    for (l = 1; l <= n1; l++)		    {			l1 = l;			if (l >= j)			    l1 = l + 1;			b[k][l] = a[k1][l1];		    }		}		a_inverse[j][i] = det(b, n1) / d1 * v * w;	    }	}    }    free_matrix(b, 1, n, 1);}/********************************************************************************//*                                                                              *//*           FUNCTION NAME     :   det()                                        *//*                                                                              *//*           SYNOPSIS          :   float det(input_matrix,nl)                   *//*                                                                              *//*           DESCRIPTION       :   This function returns the determinant of a   *//*                                  given float matrix                          *//*                                                                              *//*           FUNCTIONS CALLED  :   matrix().                                    *//*                                                                              *//*           CALLING FUNCITONS :   inverse(),                                   *//*                                 p_equalities().                              *//*                                                                              *//*           AUTHOR            :   Swarnalatha Swaminathan                      *//*                                                                              *//*           DATE              :   1/17/92                                      *//*                                                                              *//*                                                                              *//*           REV            DATE            BY           DESCRIPTION            *//*           ---            ----            --           -----------            *//*                                                                              *//*                                                                              *//********************************************************************************/float det(input_matrix, nl)    MATRIX          input_matrix;	    /* input float matrix */    int             nl;			    /* order of the matrix */{    int             ia, ib, i1, j1, n2, nz, n3, l, l1, m, m1;    float           d, x;    MATRIX          temp_input_matrix, b1;    temp_input_matrix = matrix(1, nl, 1, nl);    b1 = matrix(1, nl, 1, nl);    for (i1 = 1; i1 <= nl; i1++)	for (j1 = 1; j1 <= nl; j1++)	    temp_input_matrix[i1][j1] = input_matrix[i1][j1];    d = 1.0;    for (ia = 1; ia <= nl; ia++)    {	x = -1.0;	n2 = nl - ia + 1;	n3 = n2 - 1;	nz = 0;	for (ib = 1; ib <= n2; ib++)	    if (temp_input_matrix[ib][1] != 0.0)		nz = ib;	if (nz == 0.0)	    d = 0.0;	else	{	    for (i1 = 1; i1 <= nz; i1++)		x = -x;	    d *= temp_input_matrix[nz][1] * x;	    for (l = 1; l <= n3; l++)	    {		l1 = l;		if (l >= nz)		    l1 = l + 1;		for (m = 1; m <= n3; m++)		{		    m1 = m + 1;		    b1[l][m] = temp_input_matrix[l1][m1] - temp_input_matrix[l1][1]			/ temp_input_matrix[nz][1] * temp_input_matrix[nz][m1];		}	    }	}	for (i1 = 1; i1 <= n3; i1++)	    for (j1 = 1; j1 <= n3; j1++)		temp_input_matrix[i1][j1] = b1[i1][j1];    }    free_matrix(b1, 1, nl, 1);    free_matrix(temp_input_matrix, 1, nl, 1);    return (d);}