Mercurial > octave
view libinterp/corefcn/gsvd.cc @ 22321:3d18c22e6e3d
gsvd.cc: Clean up to follow Octave coding standards.
* gsvd.cc: Rewrite docstring. Don't check nargout for print_usage().
Dont use 'return retval' after print_usage() or error().
Follow Octave coding convetions in BIST tests.
author | Rik <rik@octave.org> |
---|---|
date | Tue, 16 Aug 2016 21:38:58 -0700 |
parents | 9fc91bb2aec3 |
children | bac0d6f07a3e |
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line source
// Copyright (C) 1996, 1997 John W. Eaton // Copyright (C) 2006, 2010 Pascal Dupuis <Pascal.Dupuis@uclouvain.be> // Copyright (C) 2016 Barbara Lócsi // // This program is free software; you can redistribute it and/or modify it under // the terms of the GNU General Public License as published by the Free Software // Foundation; either version 3 of the License, or (at your option) any later // version. // // This program is distributed in the hope that it will be useful, but WITHOUT // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more // details. // // You should have received a copy of the GNU General Public License along with // this program; if not, see <http://www.gnu.org/licenses/>. #ifdef HAVE_CONFIG_H # include <config.h> #endif #include "dMatrix.h" #include "CMatrix.h" #include "dDiagMatrix.h" #include "gsvd.h" #include "defun.h" #include "defun-int.h" #include "error.h" #include "errwarn.h" #include "utils.h" #include "ovl.h" #include "ov.h" template <typename T> static typename gsvd<T>::Type gsvd_type (int nargout) { return ((nargout == 0 || nargout == 1) ? gsvd<T>::Type::sigma_only : (nargout > 5) ? gsvd<T>::Type::std : gsvd<T>::Type::economy); } DEFUN (gsvd, args, nargout, doc: /* -*- texinfo -*- @deftypefn {} {@var{s} =} gsvd (@var{a}, @var{b}) @deftypefnx {} {[@var{u}, @var{v}, @var{c}, @var{s}, @var{x}] =} gsvd (@var{a}, @var{b}) @deftypefnx {} {[@var{u}, @var{v}, @var{c}, @var{s}, @var{x}, @var{r}] =} gsvd (@var{a}, @var{b}) @cindex generalized singular value decomposition Compute the generalized singular value decomposition of (@var{a}, @var{b}): @tex $$ U^H A X = [I 0; 0 C] [0 R] V^H B X = [0 S; 0 0] [0 R] C*C + S*S = eye (columns (A)) I and 0 are padding matrices of suitable size R is upper triangular $$ @end tex @ifinfo @example @group u' * a * x = [I 0; 0 c] * [0 r] v' * b * x = [0 s; 0 0] * [0 r] c * c + s * s = eye (columns (a)) I and 0 are padding matrices of suitable size r is upper triangular @end group @end example @end ifinfo The function @code{gsvd} normally returns the vector of generalized singular values @tex diag (C) ./ diag (S). @end tex @ifinfo diag (r) ./ diag (s). @end ifinfo If asked for five return values, it computes @tex $U$, $V$, and $X$. @end tex @ifinfo U, V, and X. @end ifinfo With a sixth output argument, it also returns @tex R, @end tex @ifinfo r, @end ifinfo The common upper triangular right term. Other authors, like @nospell{S. Van Huffel}, define this transformation as the simultaneous diagonalization of the input matrices, this can be achieved by multiplying @tex X @end tex @ifinfo x @end ifinfo by the inverse of @tex [I 0; 0 R]. @end tex @ifinfo [I 0; 0 r]. @end ifinfo For example, @example gsvd (hilb (3), [1 2 3; 3 2 1]) @result{} 0.1055705 0.0031759 @end example @noindent and @example [u, v, c, s, x, r] = gsvd (hilb (3), [1 2 3; 3 2 1]) @result{} u = -0.965609 0.240893 0.097825 -0.241402 -0.690927 -0.681429 -0.096561 -0.681609 0.725317 v = -0.41974 0.90765 -0.90765 -0.41974 c = 0.10499 0.00000 0.00000 0.00318 s = 0.99447 0.00000 0.00000 0.99999 x = 0.408248 0.902199 0.139179 -0.816497 0.429063 -0.386314 0.408248 -0.044073 -0.911806 r = -0.14093 -1.24345 0.43737 0.00000 -3.90043 2.57818 0.00000 0.00000 -2.52599 @end example The code is a wrapper to the corresponding @sc{lapack} dggsvd and zggsvd routines. @end deftypefn */) { if (args.length () != 2) print_usage (); octave_value_list retval; octave_value argA = args(0); octave_value argB = args(1); octave_idx_type nr = argA.rows (); octave_idx_type nc = argA.columns (); octave_idx_type np = argB.columns (); if (nr == 0 || nc == 0) { if (nargout == 5) retval = ovl (identity_matrix (nc, nc), identity_matrix (nc, nc), Matrix (nr, nc), identity_matrix (nr, nr), identity_matrix (nr, nr)); else if (nargout == 6) retval = ovl (identity_matrix (nc, nc), identity_matrix (nc, nc), Matrix (nr, nc), identity_matrix (nr, nr), identity_matrix (nr, nr), identity_matrix (nr, nr)); else retval = ovl (Matrix (0, 1)); } else { if (nc != np) print_usage (); if (argA.is_real_type () && argB.is_real_type ()) { Matrix tmpA = argA.matrix_value (); Matrix tmpB = argB.matrix_value (); // FIXME: This code is still using error_state if (! error_state) { if (tmpA.any_element_is_inf_or_nan ()) error ("gsvd: B cannot have Inf or NaN values"); if (tmpB.any_element_is_inf_or_nan ()) error ("gsvd: B cannot have Inf or NaN values"); gsvd<Matrix> result (tmpA, tmpB, gsvd_type<Matrix> (nargout)); // DiagMatrix sigma = result.singular_values (); if (nargout == 0 || nargout == 1) { DiagMatrix sigA = result.singular_values_A (); DiagMatrix sigB = result.singular_values_B (); for (int i = sigA.rows() - 1; i >=0; i--) sigA.dgxelem(i) /= sigB.dgxelem(i); retval = ovl (sigA.diag()); } else { if (nargout > 5) retval = ovl (result.left_singular_matrix_A (), result.left_singular_matrix_B (), result.singular_values_A (), result.singular_values_B (), result.right_singular_matrix (), result.R_matrix ()); else retval = ovl (result.left_singular_matrix_A (), result.left_singular_matrix_B (), result.singular_values_A (), result.singular_values_B (), result.right_singular_matrix ()); } } } else if (argA.is_complex_type () || argB.is_complex_type ()) { ComplexMatrix ctmpA = argA.complex_matrix_value (); ComplexMatrix ctmpB = argB.complex_matrix_value (); if (! error_state) { if (ctmpA.any_element_is_inf_or_nan ()) error ("gsvd: A cannot have Inf or NaN values"); if (ctmpB.any_element_is_inf_or_nan ()) error ("gsvd: B cannot have Inf or NaN values"); gsvd<ComplexMatrix> result (ctmpA, ctmpB, gsvd_type<ComplexMatrix> (nargout)); // DiagMatrix sigma = result.singular_values (); if (nargout == 0 || nargout == 1) { DiagMatrix sigA = result.singular_values_A (); DiagMatrix sigB = result.singular_values_B (); for (int i = sigA.rows() - 1; i >=0; i--) sigA.dgxelem(i) /= sigB.dgxelem(i); retval = ovl (sigA.diag()); } else { if (nargout > 5) retval = ovl (result.left_singular_matrix_A (), result.left_singular_matrix_B (), result.singular_values_A (), result.singular_values_B (), result.right_singular_matrix (), result.R_matrix ()); else retval = ovl (result.left_singular_matrix_A (), result.left_singular_matrix_B (), result.singular_values_A (), result.singular_values_B (), result.right_singular_matrix ()); } } } else { // Actually, can't tell which arg is at fault err_wrong_type_arg ("gsvd", argA); //err_wrong_type_arg ("gsvd", argB); } } return retval; } /* ## a few tests for gsvd.m %!shared A, A0, B, B0, U, V, C, S, X, R, D1, D2 %! A0 = randn (5, 3); %! B0 = diag ([1 2 4]); %! A = A0; %! B = B0; ## A (5x3) and B (3x3) are full rank %!test %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros (5, 3); D1(1:3, 1:3) = C; %! D2 = S; %! assert (norm (diag (C).^2 + diag (S).^2 - ones (3, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*R) <= 1e-6); %! assert (norm ((V'*B*X) - D2*R) <= 1e-6); ## A: 5x3 full rank, B: 3x3 rank deficient %!test %! B(2, 2) = 0; %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros (5, 3); D1(1, 1) = 1; D1(2:3, 2:3) = C; %! D2 = [zeros(2, 1) S; zeros(1, 3)]; %! assert (norm (diag (C).^2 + diag (S).^2 - ones (2, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*R) <= 1e-6); %! assert (norm ((V'*B*X) - D2*R) <= 1e-6); ## A: 5x3 rank deficient, B: 3x3 full rank %!test %! B = B0; %! A(:, 3) = 2*A(:, 1) - A(:, 2); %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros(5, 3); D1(1:3, 1:3) = C; %! D2 = S; %! assert (norm (diag (C).^2 + diag (S).^2 - ones (3, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*R) <= 1e-6); %! assert (norm ((V'*B*X) - D2*R) <= 1e-6); ## A and B are both rank deficient %!test %! B(:, 3) = 2*B(:, 1) - B(:, 2); %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros(5, 2); D1(1:2, 1:2) = C; %! D2 = [S; zeros(1, 2)]; %! assert (norm (diag (C).^2 + diag (S).^2 - ones (2, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*[zeros(2, 1) R]) <= 1e-6); %! assert (norm ((V'*B*X) - D2*[zeros(2, 1) R]) <= 1e-6); ## A (now 3x5) and B (now 5x5) are full rank %!test %! A = A0.'; %! B0 = diag ([1 2 4 8 16]); %! B = B0; %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = [C zeros(3,2)]; %! D2 = [S zeros(3,2); zeros(2, 3) eye(2)]; %! assert (norm (diag (C).^2 + diag (S).^2 - ones (3, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*R) <= 1e-6); %! assert (norm ((V'*B*X) - D2*R) <= 1e-6); ## A: 3x5 full rank, B: 5x5 rank deficient %!test %! B(2, 2) = 0; %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros(3, 5); D1(1, 1) = 1; D1(2:3, 2:3) = C; %! D2 = zeros(5, 5); D2(1:2, 2:3) = S; D2(3:4, 4:5) = eye (2); %! assert (norm (diag (C).^2 + diag (S).^2 - ones (2, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*R) <= 1e-6); %! assert (norm ((V'*B*X) - D2*R) <= 1e-6); ## A: 3x5 rank deficient, B: 5x5 full rank %!test %! B = B0; %! A(3, :) = 2*A(1, :) - A(2, :); %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros (3, 5); D1(1:3, 1:3) = C; %! D2 = zeros (5, 5); D2(1:3, 1:3) = S; D2(4:5, 4:5) = eye (2); %! assert (norm (diag (C).^2 + diag (S).^2 - ones (3, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*R) <= 1e-6); %! assert (norm ((V'*B*X) - D2*R) <= 1e-6); ## A and B are both rank deficient %!test %! A = A0.'; B = B0.'; %! A(:, 3) = 2*A(:, 1) - A(:, 2); %! B(:, 3) = 2*B(:, 1) - B(:, 2); %! [U, V, C, S, X, R]=gsvd (A, B); %! D1 = zeros(3, 4); D1(1:3, 1:3) = C; %! D2 = eye (4); D2(1:3, 1:3) = S; D2(5,:) = 0; %! assert (norm (diag (C).^2 + diag (S).^2 - ones (3, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*[zeros(4, 1) R]) <= 1e-6); %! assert (norm ((V'*B*X) - D2*[zeros(4, 1) R]) <= 1e-6); ## A: 5x3 complex full rank, B: 3x3 complex full rank %!test %! A0 = A0 + j*randn (5, 3); %! B0 = diag ([1 2 4]) + j*diag ([4 -2 -1]); %! A = A0; %! B = B0; %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros(5, 3); D1(1:3, 1:3) = C; %! D2 = S; %! assert (norm (diag (C).^2 + diag (S).^2 - ones (3, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*R) <= 1e-6); %! assert (norm ((V'*B*X) - D2*R) <= 1e-6); ## A: 5x3 complex full rank, B: 3x3 complex rank deficient %!test %! B(2, 2) = 0; %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros(5, 3); D1(1, 1) = 1; D1(2:3, 2:3) = C; %! D2 = [zeros(2, 1) S; zeros(1, 3)]; %! assert (norm (diag (C).^2 + diag (S).^2 - ones (2, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*R) <= 1e-6); %! assert (norm ((V'*B*X) - D2*R) <= 1e-6); ## A: 5x3 complex rank deficient, B: 3x3 complex full rank %!test %! B = B0; %! A(:, 3) = 2*A(:, 1) - A(:, 2); %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros(5, 3); D1(1:3, 1:3) = C; %! D2 = S; %! assert (norm (diag (C).^2 + diag (S).^2 - ones (3, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*R) <= 1e-6); %! assert (norm ((V'*B*X) - D2*R) <= 1e-6); ## A (5x3) and B (3x3) are both complex rank deficient %!test %! B(:, 3) = 2*B(:, 1) - B(:, 2); %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros(5, 2); D1(1:2, 1:2) = C; %! D2 = [S; zeros(1, 2)]; %! assert (norm (diag (C).^2 + diag (S).^2 - ones (2, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*[zeros(2, 1) R]) <= 1e-6); %! assert (norm ((V'*B*X) - D2*[zeros(2, 1) R]) <= 1e-6); ## A (now 3x5) complex and B (now 5x5) complex are full rank ## now, A is 3x5 %!test %! A = A0.'; %! B0 = diag ([1 2 4 8 16]) + j*diag ([-5 4 -3 2 -1]); %! B = B0; %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = [C zeros(3,2)]; %! D2 = [S zeros(3,2); zeros(2, 3) eye(2)]; %! assert (norm (diag (C).^2 + diag (S).^2 - ones (3, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*R) <= 1e-6); %! assert (norm ((V'*B*X) - D2*R) <= 1e-6); ## A: 3x5 complex full rank, B: 5x5 complex rank deficient %!test %! B(2, 2) = 0; %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros(3, 5); D1(1, 1) = 1; D1(2:3, 2:3) = C; %! D2 = zeros(5,5); D2(1:2, 2:3) = S; D2(3:4, 4:5) = eye (2); %! assert (norm (diag (C).^2 + diag (S).^2 - ones (2, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*R) <= 1e-6); %! assert (norm ((V'*B*X) - D2*R) <= 1e-6); ## A: 3x5 complex rank deficient, B: 5x5 complex full rank %!test %! B = B0; %! A(3, :) = 2*A(1, :) - A(2, :); %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros(3, 5); D1(1:3, 1:3) = C; %! D2 = zeros(5,5); D2(1:3, 1:3) = S; D2(4:5, 4:5) = eye (2); %! assert (norm (diag (C).^2 + diag (S).^2 - ones (3, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*R) <= 1e-6); %! assert (norm ((V'*B*X) - D2*R) <= 1e-6); ## A and B are both complex rank deficient %!test %! A = A0.'; %! B = B0.'; %! A(:, 3) = 2*A(:, 1) - A(:, 2); %! B(:, 3) = 2*B(:, 1) - B(:, 2); %! [U, V, C, S, X, R] = gsvd (A, B); %! D1 = zeros(3, 4); D1(1:3, 1:3) = C; %! D2 = eye (4); D2(1:3, 1:3) = S; D2(5,:) = 0; %! assert (norm (diag (C).^2 + diag (S).^2 - ones (3, 1)) <= 1e-6); %! assert (norm ((U'*A*X) - D1*[zeros(4, 1) R]) <= 1e-6); %! assert (norm ((V'*B*X) - D2*[zeros(4, 1) R]) <= 1e-6); */