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author | Nao Pross <np@0hm.ch> | 2024-02-12 14:52:43 +0100 |
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committer | Nao Pross <np@0hm.ch> | 2024-02-12 14:52:43 +0100 |
commit | eda5bc26f44ee9a6f83dcf8c91f17296d7fc509d (patch) | |
tree | bc2efa38ff4e350f9a111ac87065cd7ae9a911c7 /src/armadillo/include/armadillo_bits/op_roots_meat.hpp | |
download | fsisotool-eda5bc26f44ee9a6f83dcf8c91f17296d7fc509d.tar.gz fsisotool-eda5bc26f44ee9a6f83dcf8c91f17296d7fc509d.zip |
Move into version control
Diffstat (limited to 'src/armadillo/include/armadillo_bits/op_roots_meat.hpp')
-rw-r--r-- | src/armadillo/include/armadillo_bits/op_roots_meat.hpp | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/armadillo/include/armadillo_bits/op_roots_meat.hpp b/src/armadillo/include/armadillo_bits/op_roots_meat.hpp new file mode 100644 index 0000000..1e09120 --- /dev/null +++ b/src/armadillo/include/armadillo_bits/op_roots_meat.hpp @@ -0,0 +1,140 @@ +// 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_roots +//! @{ + + + +template<typename T1> +inline +void +op_roots::apply(Mat< std::complex<typename T1::pod_type> >& out, const mtOp<std::complex<typename T1::pod_type>, T1, op_roots>& expr) + { + arma_extra_debug_sigprint(); + + const bool status = op_roots::apply_direct(out, expr.m); + + if(status == false) + { + out.soft_reset(); + arma_stop_runtime_error("roots(): eigen decomposition failed"); + } + } + + + +template<typename T1> +inline +bool +op_roots::apply_direct(Mat< std::complex<typename T1::pod_type> >& out, const Base<typename T1::elem_type, T1>& X) + { + arma_extra_debug_sigprint(); + + typedef std::complex<typename T1::pod_type> out_eT; + + const quasi_unwrap<T1> U(X.get_ref()); + + bool status = false; + + if(U.is_alias(out)) + { + Mat<out_eT> tmp; + + status = op_roots::apply_noalias(tmp, U.M); + + out.steal_mem(tmp); + } + else + { + status = op_roots::apply_noalias(out, U.M); + } + + return status; + } + + + +template<typename eT> +inline +bool +op_roots::apply_noalias(Mat< std::complex<typename get_pod_type<eT>::result> >& out, const Mat<eT>& X) + { + arma_extra_debug_sigprint(); + + typedef typename get_pod_type<eT>::result T; + + typedef std::complex<typename get_pod_type<eT>::result> out_eT; + + arma_debug_check( (X.is_vec() == false), "roots(): given object must be a vector" ); + + if(X.internal_has_nonfinite()) { return false; } + + // treat X as a column vector + + const Col<eT> Y( const_cast<eT*>(X.memptr()), X.n_elem, false, false); + + const T Y_max = (Y.is_empty() == false) ? T(max(abs(Y))) : T(0); + + if(Y_max == T(0)) { out.set_size(1,0); return true; } + + const uvec indices = find( Y / Y_max ); + + const uword n_tail_zeros = (indices.n_elem > 0) ? uword( (Y.n_elem-1) - indices[indices.n_elem-1] ) : uword(0); + + const Col<eT> Z = Y.subvec( indices[0], indices[indices.n_elem-1] ); + + if(Z.n_elem >= uword(2)) + { + Mat<eT> tmp; + + if(Z.n_elem == uword(2)) + { + tmp.set_size(1,1); + + tmp[0] = -Z[1] / Z[0]; + } + else + { + tmp = diagmat(ones< Col<eT> >(Z.n_elem - 2), -1); + + tmp.row(0) = strans(-Z.subvec(1, Z.n_elem-1) / Z[0]); + } + + Mat<out_eT> junk; + + const bool status = auxlib::eig_gen(out, junk, false, tmp); + + if(status == false) { return false; } + + if(n_tail_zeros > 0) + { + out.resize(out.n_rows + n_tail_zeros, 1); + } + } + else + { + out.zeros(n_tail_zeros,1); + } + + return true; + } + + + +//! @} |