Mercurial > hg > segmenter-vamp-plugin
diff armadillo-2.4.4/include/armadillo_bits/fn_det.hpp @ 0:8b6102e2a9b0
Armadillo Library
author | maxzanoni76 <max.zanoni@eecs.qmul.ac.uk> |
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date | Wed, 11 Apr 2012 09:27:06 +0100 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/armadillo-2.4.4/include/armadillo_bits/fn_det.hpp Wed Apr 11 09:27:06 2012 +0100 @@ -0,0 +1,124 @@ +// Copyright (C) 2008-2011 NICTA (www.nicta.com.au) +// Copyright (C) 2008-2011 Conrad Sanderson +// +// This file is part of the Armadillo C++ library. +// It is provided without any warranty of fitness +// for any purpose. You can redistribute this file +// and/or modify it under the terms of the GNU +// Lesser General Public License (LGPL) as published +// by the Free Software Foundation, either version 3 +// of the License or (at your option) any later version. +// (see http://www.opensource.org/licenses for more info) + + +//! \addtogroup fn_det +//! @{ + + + +//! determinant of mat +template<typename T1> +inline +arma_warn_unused +typename T1::elem_type +det + ( + const Base<typename T1::elem_type,T1>& X, + const bool slow = false, + const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0 + ) + { + arma_extra_debug_sigprint(); + + arma_ignore(junk); + + return auxlib::det(X, slow); + } + + + +//! determinant of diagmat +template<typename T1> +inline +arma_warn_unused +typename T1::elem_type +det + ( + const Op<T1, op_diagmat>& X, + const bool slow = false + ) + { + arma_extra_debug_sigprint(); + arma_ignore(slow); + + typedef typename T1::elem_type eT; + + const diagmat_proxy<T1> A(X.m); + + const uword A_n_elem = A.n_elem; + + eT val = eT(1); + + for(uword i=0; i<A_n_elem; ++i) + { + val *= A[i]; + } + + return val; + } + + + +//! determinant of inv(A), without doing the inverse operation +template<typename T1> +inline +arma_warn_unused +typename T1::elem_type +det + ( + const Op<T1,op_inv>& in, + const bool slow = false, + const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0 + ) + { + arma_extra_debug_sigprint(); + arma_ignore(junk); + + typedef typename T1::elem_type eT; + + eT tmp = det(in.m, slow); + arma_warn( (tmp == eT(0)), "det(): warning: denominator is zero" ); + + return eT(1) / tmp; + } + + + +//! determinant of trans(A) +template<typename T1> +inline +arma_warn_unused +typename T1::elem_type +det + ( + const Op<T1,op_htrans>& in, + const bool slow = false, + const typename arma_blas_type_only<typename T1::elem_type>::result* junk1 = 0, + const typename arma_not_cx<typename T1::elem_type>::result* junk2 = 0 + ) + { + arma_extra_debug_sigprint(); + arma_ignore(junk1); + arma_ignore(junk2); + + typedef typename T1::elem_type eT; + + const unwrap<T1> tmp(in.m); + const Mat<eT>& X = tmp.M; + + return det(X, slow); + } + + + +//! @}