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Diffstat (limited to 'src/armadillo/include/armadillo_bits/glue_polyfit_meat.hpp')
-rw-r--r-- | src/armadillo/include/armadillo_bits/glue_polyfit_meat.hpp | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/src/armadillo/include/armadillo_bits/glue_polyfit_meat.hpp b/src/armadillo/include/armadillo_bits/glue_polyfit_meat.hpp new file mode 100644 index 0000000..3969c75 --- /dev/null +++ b/src/armadillo/include/armadillo_bits/glue_polyfit_meat.hpp @@ -0,0 +1,133 @@ +// 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 glue_polyfit +//! @{ + + + +template<typename eT> +inline +bool +glue_polyfit::apply_noalias(Mat<eT>& out, const Col<eT>& X, const Col<eT>& Y, const uword N) + { + arma_extra_debug_sigprint(); + + // create Vandermonde matrix + + Mat<eT> V(X.n_elem, N+1, arma_nozeros_indicator()); + + V.tail_cols(1).ones(); + + for(uword i=1; i <= N; ++i) + { + const uword j = N-i; + + Col<eT> V_col_j (V.colptr(j ), V.n_rows, false, false); + Col<eT> V_col_jp1(V.colptr(j+1), V.n_rows, false, false); + + V_col_j = V_col_jp1 % X; + } + + Mat<eT> Q; + Mat<eT> R; + + const bool status1 = auxlib::qr_econ(Q, R, V); + + if(status1 == false) { return false; } + + const bool status2 = auxlib::solve_trimat_fast(out, R, (Q.t() * Y), uword(0)); + + if(status2 == false) { return false; } + + return true; + } + + + +template<typename T1, typename T2> +inline +bool +glue_polyfit::apply_direct(Mat<typename T1::elem_type>& out, const Base<typename T1::elem_type,T1>& X_expr, const Base<typename T1::elem_type, T2>& Y_expr, const uword N) + { + arma_extra_debug_sigprint(); + + typedef typename T1::elem_type eT; + + const quasi_unwrap<T1> UX(X_expr.get_ref()); + const quasi_unwrap<T2> UY(Y_expr.get_ref()); + + const Mat<eT>& X = UX.M; + const Mat<eT>& Y = UY.M; + + arma_debug_check + ( + ( ((X.is_vec() == false) && (X.is_empty() == false)) || ((Y.is_vec() == false) && (Y.is_empty() == false)) ), + "polyfit(): given object must be a vector" + ); + + arma_debug_check( (X.n_elem != Y.n_elem), "polyfit(): given vectors must have the same number of elements" ); + + if(X.n_elem == 0) + { + out.reset(); + return true; + } + + arma_debug_check( (N >= X.n_elem), "polyfit(): N must be less than the number of elements in X" ); + + const Col<eT> X_as_colvec( const_cast<eT*>(X.memptr()), X.n_elem, false, false); + const Col<eT> Y_as_colvec( const_cast<eT*>(Y.memptr()), Y.n_elem, false, false); + + bool status = false; + + if(UX.is_alias(out) || UY.is_alias(out)) + { + Mat<eT> tmp; + status = glue_polyfit::apply_noalias(tmp, X_as_colvec, Y_as_colvec, N); + out.steal_mem(tmp); + } + else + { + status = glue_polyfit::apply_noalias(out, X_as_colvec, Y_as_colvec, N); + } + + return status; + } + + + +template<typename T1, typename T2> +inline +void +glue_polyfit::apply(Mat<typename T1::elem_type>& out, const Glue<T1,T2,glue_polyfit>& expr) + { + arma_extra_debug_sigprint(); + + const bool status = glue_polyfit::apply_direct(out, expr.A, expr.B, expr.aux_uword); + + if(status == false) + { + out.soft_reset(); + arma_stop_runtime_error("polyfit(): failed"); + } + } + + + +//! @} |