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Diffstat (limited to 'src/armadillo/include/armadillo_bits/op_pinv_meat.hpp')
-rw-r--r-- | src/armadillo/include/armadillo_bits/op_pinv_meat.hpp | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/src/armadillo/include/armadillo_bits/op_pinv_meat.hpp b/src/armadillo/include/armadillo_bits/op_pinv_meat.hpp new file mode 100644 index 0000000..326a0be --- /dev/null +++ b/src/armadillo/include/armadillo_bits/op_pinv_meat.hpp @@ -0,0 +1,313 @@ +// SPDX-License-Identifier: Apache-2.0 +// +// Copyright 2008-2016 Conrad Sanderson (http://conradsanderson.id.au) +// Copyright 2008-2016 National ICT Australia (NICTA) +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +// ------------------------------------------------------------------------ + + + +//! \addtogroup op_pinv +//! @{ + + + +template<typename T1> +inline +void +op_pinv_default::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_pinv_default>& in) + { + arma_extra_debug_sigprint(); + + const bool status = op_pinv_default::apply_direct(out, in.m); + + if(status == false) + { + out.soft_reset(); + arma_stop_runtime_error("pinv(): svd failed"); + } + } + + + +template<typename T1> +inline +bool +op_pinv_default::apply_direct(Mat<typename T1::elem_type>& out, const Base<typename T1::elem_type,T1>& expr) + { + arma_extra_debug_sigprint(); + + typedef typename T1::pod_type T; + + constexpr T tol = T(0); + constexpr uword method_id = uword(0); + + return op_pinv::apply_direct(out, expr, tol, method_id); + } + + + +// + + + +template<typename T1> +inline +void +op_pinv::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_pinv>& in) + { + arma_extra_debug_sigprint(); + + typedef typename T1::pod_type T; + + const T tol = access::tmp_real(in.aux); + const uword method_id = in.aux_uword_a; + + const bool status = op_pinv::apply_direct(out, in.m, tol, method_id); + + if(status == false) + { + out.soft_reset(); + arma_stop_runtime_error("pinv(): svd failed"); + } + } + + + +template<typename T1> +inline +bool +op_pinv::apply_direct(Mat<typename T1::elem_type>& out, const Base<typename T1::elem_type,T1>& expr, typename T1::pod_type tol, const uword method_id) + { + arma_extra_debug_sigprint(); + + typedef typename T1::elem_type eT; + typedef typename T1::pod_type T; + + arma_debug_check((tol < T(0)), "pinv(): tolerance must be >= 0"); + + // method_id = 0 -> default setting + // method_id = 1 -> use standard algorithm + // method_id = 2 -> use divide and conquer algorithm + + Mat<eT> A(expr.get_ref()); + + if(A.is_empty()) { out.set_size(A.n_cols,A.n_rows); return true; } + + if(is_op_diagmat<T1>::value || A.is_diagmat()) + { + arma_extra_debug_print("op_pinv: detected diagonal matrix"); + + return op_pinv::apply_diag(out, A, tol); + } + + bool do_sym = false; + + const bool is_sym_size_ok = (A.n_rows == A.n_cols) && (A.n_rows > (is_cx<eT>::yes ? uword(20) : uword(40))); + + if( (is_sym_size_ok) && (arma_config::optimise_sym) && (auxlib::crippled_lapack(A) == false) ) + { + bool is_approx_sym = false; + bool is_approx_sympd = false; + + sym_helper::analyse_matrix(is_approx_sym, is_approx_sympd, A); + + do_sym = ((is_cx<eT>::no) ? (is_approx_sym) : (is_approx_sym && is_approx_sympd)); + } + + if(do_sym) + { + arma_extra_debug_print("op_pinv: symmetric/hermitian optimisation"); + + return op_pinv::apply_sym(out, A, tol, method_id); + } + + return op_pinv::apply_gen(out, A, tol, method_id); + } + + + +template<typename eT> +inline +bool +op_pinv::apply_diag(Mat<eT>& out, const Mat<eT>& A, typename get_pod_type<eT>::result tol) + { + arma_extra_debug_sigprint(); + + typedef typename get_pod_type<eT>::result T; + + out.zeros(A.n_cols, A.n_rows); + + const uword N = (std::min)(A.n_rows, A.n_cols); + + podarray<T> diag_abs_vals(N); + + T max_abs_Aii = T(0); + + for(uword i=0; i<N; ++i) + { + const eT Aii = A.at(i,i); + const T abs_Aii = std::abs(Aii); + + if(arma_isnan(Aii)) { return false; } + + diag_abs_vals[i] = abs_Aii; + + max_abs_Aii = (abs_Aii > max_abs_Aii) ? abs_Aii : max_abs_Aii; + } + + if(tol == T(0)) { tol = (std::max)(A.n_rows, A.n_cols) * max_abs_Aii * std::numeric_limits<T>::epsilon(); } + + for(uword i=0; i<N; ++i) + { + if(diag_abs_vals[i] >= tol) + { + const eT Aii = A.at(i,i); + + if(Aii != eT(0)) { out.at(i,i) = eT(eT(1) / Aii); } + } + } + + return true; + } + + + +template<typename eT> +inline +bool +op_pinv::apply_sym(Mat<eT>& out, const Mat<eT>& A, typename get_pod_type<eT>::result tol, const uword method_id) + { + arma_extra_debug_sigprint(); + + typedef typename get_pod_type<eT>::result T; + + Col< T> eigval; + Mat<eT> eigvec; + + const bool status = ((method_id == uword(0)) || (method_id == uword(2))) ? auxlib::eig_sym_dc(eigval, eigvec, A) : auxlib::eig_sym(eigval, eigvec, A); + + if(status == false) { return false; } + + if(eigval.n_elem == 0) { out.zeros(A.n_cols, A.n_rows); return true; } + + Col<T> abs_eigval = arma::abs(eigval); + + const uvec indices = sort_index(abs_eigval, "descend"); + + abs_eigval = abs_eigval.elem(indices); + eigval = eigval.elem(indices); + eigvec = eigvec.cols(indices); + + // set tolerance to default if it hasn't been specified + if(tol == T(0)) { tol = (std::max)(A.n_rows, A.n_cols) * abs_eigval[0] * std::numeric_limits<T>::epsilon(); } + + uword count = 0; + + for(uword i=0; i < abs_eigval.n_elem; ++i) { count += (abs_eigval[i] >= tol) ? uword(1) : uword(0); } + + if(count == 0) { out.zeros(A.n_cols, A.n_rows); return true; } + + Col<T> eigval2(count, arma_nozeros_indicator()); + + uword count2 = 0; + + for(uword i=0; i < eigval.n_elem; ++i) + { + const T abs_val = abs_eigval[i]; + const T val = eigval[i]; + + if(abs_val >= tol) { eigval2[count2] = (val != T(0)) ? T(T(1) / val) : T(0); ++count2; } + } + + const Mat<eT> eigvec_use(eigvec.memptr(), eigvec.n_rows, count, false); + + out = (eigvec_use * diagmat(eigval2)).eval() * eigvec_use.t(); + + return true; + } + + + + +template<typename eT> +inline +bool +op_pinv::apply_gen(Mat<eT>& out, Mat<eT>& A, typename get_pod_type<eT>::result tol, const uword method_id) + { + arma_extra_debug_sigprint(); + + typedef typename get_pod_type<eT>::result T; + + const uword n_rows = A.n_rows; + const uword n_cols = A.n_cols; + + // economical SVD decomposition + Mat<eT> U; + Col< T> s; + Mat<eT> V; + + if(n_cols > n_rows) { A = trans(A); } + + const bool status = ((method_id == uword(0)) || (method_id == uword(2))) ? auxlib::svd_dc_econ(U, s, V, A) : auxlib::svd_econ(U, s, V, A, 'b'); + + if(status == false) { return false; } + + // set tolerance to default if it hasn't been specified + if( (tol == T(0)) && (s.n_elem > 0) ) { tol = (std::max)(n_rows, n_cols) * s[0] * std::numeric_limits<T>::epsilon(); } + + uword count = 0; + + for(uword i=0; i < s.n_elem; ++i) { count += (s[i] >= tol) ? uword(1) : uword(0); } + + if(count == 0) { out.zeros(n_cols, n_rows); return true; } + + Col<T> s2(count, arma_nozeros_indicator()); + + uword count2 = 0; + + for(uword i=0; i < s.n_elem; ++i) + { + const T val = s[i]; + + if(val >= tol) { s2[count2] = (val > T(0)) ? T(T(1) / val) : T(0); ++count2; } + } + + const Mat<eT> U_use(U.memptr(), U.n_rows, count, false); + const Mat<eT> V_use(V.memptr(), V.n_rows, count, false); + + Mat<eT> tmp; + + if(n_rows >= n_cols) + { + // out = ( (V.n_cols > count) ? V.cols(0,count-1) : V ) * diagmat(s2) * trans( (U.n_cols > count) ? U.cols(0,count-1) : U ); + + tmp = V_use * diagmat(s2); + + out = tmp * trans(U_use); + } + else + { + // out = ( (U.n_cols > count) ? U.cols(0,count-1) : U ) * diagmat(s2) * trans( (V.n_cols > count) ? V.cols(0,count-1) : V ); + + tmp = U_use * diagmat(s2); + + out = tmp * trans(V_use); + } + + return true; + } + + + +//! @} |