// compute the inverse of a given matrix
// Guassian elimination
void invert_matrix(uint8_t *matrix, uint8_t *result, int size)
{
    int row;
    int pivotIndex;
    uint8_t currentRow[size];
    int currentRowSize = size*sizeof(uint8_t);

    get_identity_matrix(result, size);

#ifdef DEBUG
    printf("original matrix:\n");
    show_squre_matrix(matrix, size);
    printf("result: \n");
    show_squre_matrix(result,size);
#endif
    for(row=0; row<size; row++)
    {
        // check whether the leading coefficient of the current row is in the 'index'th column
        int index = row;
        memcpy(&currentRow, matrix+row*size, currentRowSize);
        pivotIndex = get_pivot_index(currentRow, index, size);
        if( pivotIndex != row )
        {
            switch_columns(matrix, result, index, pivotIndex, size);
        }

        // Normalize the pivot row
        normalize_pivot_row(matrix, result, index, size);

#ifdef DEBUG
        printf("original matrix:\n");
        show_squre_matrix(matrix, size);
        printf("result: \n");
        show_squre_matrix(result,size);
#endif
        eliminate_by_row(matrix, result, row, size);

#ifdef DEBUG
        printf("original matrix:\n");
        show_squre_matrix(matrix, size);
        printf("result: \n");
        show_squre_matrix(result,size);
#endif
    }
}
Exemple #2
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struct map_type *dfp( function func,
                      struct map_type *map_x,
                      __float128 grad_toler,
                      __float128 fx_toler,
                      const unsigned int max_iter )
{
    unsigned int iter;
    __float128 lambda, result_func_value, temp_func_value;
    struct map_type *result, *b, *grad1, *tmp, *s, *grad2,
            *g, *tmp2, *tmp3, *d, *x1, *x2, *x3, *x4, *x5;

    result = NULL;
    result_func_value = func( map_x );

    b = get_identity_matrix( map_x->j_size );
    grad1 = first_derivatives( func, map_x );
    tmp = transposition( grad1 );
    deallocate( grad1 );
    grad1 = tmp;
    for( iter = 0 ; iter < max_iter; iter++ )
	{
        tmp = multiplicate_on_value( -1, b );
        s = multiplicate( tmp, grad1 );
        deallocate( tmp );

        tmp = transposition( s );
        tmp2 = multiplicate_on_value( powf( get_euclidean_distance( s ), -1 ), tmp );
        deallocate( s );
        deallocate( tmp );
        s = tmp2;

        lambda = 1;
        lambda = line_search( func, map_x, lambda, s );
        d = multiplicate_on_value( lambda, s );

        tmp = addition( map_x, d );
        deallocate( d );
        deallocate( map_x );
        map_x = tmp;
        temp_func_value = func( map_x );
        if( result_func_value > temp_func_value )
        {
            iter = 0;
            result_func_value = temp_func_value;
            if( result != NULL )
            {
                deallocate( result );
            }
            result = clone( map_x );
        }

        grad2 = first_derivatives( func, map_x );
        tmp = transposition( grad2 );
        deallocate( grad2 );
        grad2 = tmp;
        g = subtraction( grad2, grad1 );
        deallocate( grad1 );
        grad1 = grad2;
        if( get_euclidean_distance( grad1 ) < grad_toler )
        {
            /// TODO: Нужно очистить память
            break;
        }

        tmp = transposition( s );
        x1 = multiplicate( s, tmp );
        x2 = multiplicate( s, g );
        deallocate( s );
        deallocate( tmp );

        tmp = multiplicate_on_value( lambda, x1 );
        tmp2 = get_inverse( x2 );
        tmp3 = multiplicate( tmp, tmp2 );
        deallocate( tmp );
        tmp = addition( b, tmp3 );
        deallocate( x1 );
        deallocate( x2 );
        deallocate( tmp2 );
        deallocate( tmp3 );
        deallocate( b );
        b = tmp;

        x3 = multiplicate( b, g );
        tmp = transposition( b );
        x4 = multiplicate( tmp, g );
        deallocate( tmp );

        tmp = transposition( g );
        tmp2 = multiplicate( tmp, b );
        x5 = multiplicate( tmp2, g );
        deallocate( g );
        deallocate( tmp );
        deallocate( tmp2 );

        tmp = transposition( x4 );
        tmp2 = multiplicate( x3, tmp );
        deallocate( tmp );
        tmp = get_inverse( x5 );
        tmp3 = multiplicate( tmp, tmp2 );
        deallocate( tmp );

        tmp = subtraction( b, tmp3 );
        deallocate( b );
        b = tmp;

        deallocate( tmp2 );
        deallocate( tmp3 );
        deallocate( x3 );
        deallocate( x4 );
        deallocate( x5 );
    }
    return result;
}