lambda_trans_matrix
lambda_trans_matrix_inverse (lambda_trans_matrix mat)
{
lambda_trans_matrix inverse;
int determinant;
inverse = lambda_trans_matrix_new (LTM_ROWSIZE (mat), LTM_COLSIZE (mat));
determinant = lambda_matrix_inverse (LTM_MATRIX (mat), LTM_MATRIX (inverse),
LTM_ROWSIZE (mat));
LTM_DENOMINATOR (inverse) = determinant;
return inverse;
}
void
lambda_matrix_project_to_null (lambda_matrix B, int rowsize,
int colsize, int k, lambda_vector x)
{
lambda_matrix M1, M2, M3, I;
int determinant;
/* Compute c(I-B^T inv(B B^T) B) e sub k. */
/* M1 is the transpose of B. */
M1 = lambda_matrix_new (colsize, colsize);
lambda_matrix_transpose (B, M1, rowsize, colsize);
/* M2 = B * B^T */
M2 = lambda_matrix_new (colsize, colsize);
lambda_matrix_mult (B, M1, M2, rowsize, colsize, rowsize);
/* M3 = inv(M2) */
M3 = lambda_matrix_new (colsize, colsize);
determinant = lambda_matrix_inverse (M2, M3, rowsize);
/* M2 = B^T (inv(B B^T)) */
lambda_matrix_mult (M1, M3, M2, colsize, rowsize, rowsize);
/* M1 = B^T (inv(B B^T)) B */
lambda_matrix_mult (M2, B, M1, colsize, rowsize, colsize);
lambda_matrix_negate (M1, M1, colsize, colsize);
I = lambda_matrix_new (colsize, colsize);
lambda_matrix_id (I, colsize);
lambda_matrix_add_mc (I, determinant, M1, 1, M2, colsize, colsize);
lambda_matrix_get_column (M2, colsize, k - 1, x);
}