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Diffstat (limited to 'src/armadillo/include/armadillo_bits/spglue_min_meat.hpp')
-rw-r--r-- | src/armadillo/include/armadillo_bits/spglue_min_meat.hpp | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/src/armadillo/include/armadillo_bits/spglue_min_meat.hpp b/src/armadillo/include/armadillo_bits/spglue_min_meat.hpp new file mode 100644 index 0000000..cdfc197 --- /dev/null +++ b/src/armadillo/include/armadillo_bits/spglue_min_meat.hpp @@ -0,0 +1,222 @@ +// 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 spglue_min +//! @{ + + + +template<typename T1, typename T2> +inline +void +spglue_min::apply(SpMat<typename T1::elem_type>& out, const SpGlue<T1,T2,spglue_min>& X) + { + arma_extra_debug_sigprint(); + + typedef typename T1::elem_type eT; + + const SpProxy<T1> pa(X.A); + const SpProxy<T2> pb(X.B); + + const bool is_alias = pa.is_alias(out) || pb.is_alias(out); + + if(is_alias == false) + { + spglue_min::apply_noalias(out, pa, pb); + } + else + { + SpMat<eT> tmp; + + spglue_min::apply_noalias(tmp, pa, pb); + + out.steal_mem(tmp); + } + } + + + +template<typename eT, typename T1, typename T2> +inline +void +spglue_min::apply_noalias(SpMat<eT>& out, const SpProxy<T1>& pa, const SpProxy<T2>& pb) + { + arma_extra_debug_sigprint(); + + arma_debug_assert_same_size(pa.get_n_rows(), pa.get_n_cols(), pb.get_n_rows(), pb.get_n_cols(), "element-wise min()"); + + const uword max_n_nonzero = pa.get_n_nonzero() + pb.get_n_nonzero(); + + // Resize memory to upper bound + out.reserve(pa.get_n_rows(), pa.get_n_cols(), max_n_nonzero); + + // Now iterate across both matrices. + typename SpProxy<T1>::const_iterator_type x_it = pa.begin(); + typename SpProxy<T1>::const_iterator_type x_end = pa.end(); + + typename SpProxy<T2>::const_iterator_type y_it = pb.begin(); + typename SpProxy<T2>::const_iterator_type y_end = pb.end(); + + uword count = 0; + + while( (x_it != x_end) || (y_it != y_end) ) + { + eT out_val; + + const uword x_it_col = x_it.col(); + const uword x_it_row = x_it.row(); + + const uword y_it_col = y_it.col(); + const uword y_it_row = y_it.row(); + + bool use_y_loc = false; + + if(x_it == y_it) + { + out_val = elem_min(eT(*x_it), eT(*y_it)); + + ++x_it; + ++y_it; + } + else + { + if((x_it_col < y_it_col) || ((x_it_col == y_it_col) && (x_it_row < y_it_row))) // if y is closer to the end + { + out_val = elem_min(eT(*x_it), eT(0)); + + ++x_it; + } + else + { + out_val = elem_min(eT(*y_it), eT(0)); + + ++y_it; + + use_y_loc = true; + } + } + + if(out_val != eT(0)) + { + access::rw(out.values[count]) = out_val; + + const uword out_row = (use_y_loc == false) ? x_it_row : y_it_row; + const uword out_col = (use_y_loc == false) ? x_it_col : y_it_col; + + access::rw(out.row_indices[count]) = out_row; + access::rw(out.col_ptrs[out_col + 1])++; + ++count; + } + + arma_check( (count > max_n_nonzero), "internal error: spglue_min::apply_noalias(): count > max_n_nonzero" ); + } + + const uword out_n_cols = out.n_cols; + + uword* col_ptrs = access::rwp(out.col_ptrs); + + // Fix column pointers to be cumulative. + for(uword c = 1; c <= out_n_cols; ++c) + { + col_ptrs[c] += col_ptrs[c - 1]; + } + + if(count < max_n_nonzero) + { + if(count <= (max_n_nonzero/2)) + { + out.mem_resize(count); + } + else + { + // quick resize without reallocating memory and copying data + access::rw( out.n_nonzero) = count; + access::rw( out.values[count]) = eT(0); + access::rw(out.row_indices[count]) = uword(0); + } + } + } + + + +template<typename eT> +inline +void +spglue_min::apply_noalias(SpMat<eT>& out, const SpMat<eT>& A, const SpMat<eT>& B) + { + arma_extra_debug_sigprint(); + + const SpProxy< SpMat<eT> > pa(A); + const SpProxy< SpMat<eT> > pb(B); + + spglue_min::apply_noalias(out, pa, pb); + } + + + +template<typename eT, typename T1, typename T2> +inline +void +spglue_min::dense_sparse_min(Mat<eT>& out, const Base<eT,T1>& X, const SpBase<eT,T2>& Y) + { + arma_extra_debug_sigprint(); + + // NOTE: this function assumes there is no aliasing between matrix 'out' and X + + const Proxy<T1> pa(X.get_ref()); + const SpProxy<T2> pb(Y.get_ref()); + + const uword n_rows = pa.get_n_rows(); + const uword n_cols = pa.get_n_cols(); + + arma_debug_assert_same_size( n_rows, n_cols, pb.get_n_rows(), pb.get_n_cols(), "element-wise min()" ); + + out.set_size(n_rows, n_cols); + + for(uword c=0; c < n_cols; ++c) + for(uword r=0; r < n_rows; ++r) + { + out.at(r,c) = elem_min(pa.at(r,c), pb.at(r,c)); + } + } + + + +// min of non-complex elements +template<typename eT> +inline +typename enable_if2<is_cx<eT>::no, eT>::result +spglue_min::elem_min(const eT& a, const eT& b) + { + return (std::min)(a, b); + } + + + +// min of complex elements +template<typename eT> +inline +typename enable_if2<is_cx<eT>::yes, eT>::result +spglue_min::elem_min(const eT& a, const eT& b) + { + return (std::abs(a) < std::abs(b)) ? a : b; + } + + + +//! @} |