Ginkgo Generated from branch based on main. Ginkgo version 1.10.0
A numerical linear algebra library targeting many-core architectures
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matrix_assembly_data.hpp
1// SPDX-FileCopyrightText: 2017 - 2024 The Ginkgo authors
2//
3// SPDX-License-Identifier: BSD-3-Clause
4
5#ifndef GKO_PUBLIC_CORE_BASE_MATRIX_ASSEMBLY_DATA_HPP_
6#define GKO_PUBLIC_CORE_BASE_MATRIX_ASSEMBLY_DATA_HPP_
7
8
9#include <algorithm>
10#include <iterator>
11#include <numeric>
12#include <tuple>
13#include <unordered_map>
14
15#include <ginkgo/core/base/dim.hpp>
16#include <ginkgo/core/base/math.hpp>
17#include <ginkgo/core/base/matrix_data.hpp>
18#include <ginkgo/core/base/types.hpp>
19#include <ginkgo/core/base/utils.hpp>
20
21
22namespace gko {
23namespace detail {
24
25
26template <typename IndexType>
27struct symbolic_nonzero_hash {
28 symbolic_nonzero_hash() = default;
29
30 explicit symbolic_nonzero_hash(size_type num_cols) noexcept
31 : num_cols_{num_cols}
32 {}
33
34 std::size_t operator()(std::pair<IndexType, IndexType> nnz) const noexcept
35 {
36 return static_cast<std::size_t>(nnz.first) * num_cols_ + nnz.second;
37 }
38
39 size_type num_cols_;
40};
41
42
43} // namespace detail
44
45
58template <typename ValueType = default_precision, typename IndexType = int32>
59class matrix_assembly_data {
60public:
61 using value_type = ValueType;
62 using index_type = IndexType;
63
64 explicit matrix_assembly_data(dim<2> size)
65 : size_{size},
66 nonzeros_(0, detail::symbolic_nonzero_hash<index_type>(size_[1]))
67 {}
68
78 void add_value(index_type row, index_type col, value_type val)
79 {
80 auto ind = std::make_pair(row, col);
81 nonzeros_[ind] += val;
82 }
83
92 void set_value(index_type row, index_type col, value_type val)
93 {
94 auto ind = std::make_pair(row, col);
95 nonzeros_[ind] = val;
96 }
97
105 value_type get_value(index_type row, index_type col)
106 {
107 const auto it = nonzeros_.find(std::make_pair(row, col));
108 if (it == nonzeros_.end()) {
109 return zero<value_type>();
110 } else {
111 return it->second;
112 }
113 }
114
122 bool contains(index_type row, index_type col)
123 {
124 return nonzeros_.find(std::make_pair(row, col)) != nonzeros_.end();
125 }
126
128 dim<2> get_size() const noexcept { return size_; }
129
132 {
133 return nonzeros_.size();
134 }
135
141 {
142 using output_type = matrix_data<ValueType, IndexType>;
143 using nonzero_type = typename output_type::nonzero_type;
144 using entry_type =
145 std::pair<std::pair<index_type, index_type>, value_type>;
146 output_type data{size_};
147 data.nonzeros.reserve(nonzeros_.size());
148 std::transform(nonzeros_.begin(), nonzeros_.end(),
149 std::back_inserter(data.nonzeros), [](entry_type entry) {
150 return nonzero_type{entry.first.first,
151 entry.first.second,
152 entry.second};
153 });
154 data.sort_row_major();
155 return data;
156 }
157
158private:
162 dim<2> size_;
163
171 std::unordered_map<std::pair<index_type, index_type>, value_type,
172 detail::symbolic_nonzero_hash<index_type>>
173 nonzeros_;
174};
175
176
177} // namespace gko
178
179
180#endif // GKO_PUBLIC_CORE_BASE_MATRIX_ASSEMBLY_DATA_HPP_
void add_value(index_type row, index_type col, value_type val)
Sets the matrix value at (row, col).
Definition matrix_assembly_data.hpp:78
void set_value(index_type row, index_type col, value_type val)
Sets the matrix value at (row, col).
Definition matrix_assembly_data.hpp:92
size_type get_num_stored_elements() const noexcept
Definition matrix_assembly_data.hpp:131
bool contains(index_type row, index_type col)
Returns true iff the matrix contains an entry at (row, col).
Definition matrix_assembly_data.hpp:122
value_type get_value(index_type row, index_type col)
Gets the matrix value at (row, col).
Definition matrix_assembly_data.hpp:105
dim< 2 > get_size() const noexcept
Definition matrix_assembly_data.hpp:128
matrix_data< ValueType, IndexType > get_ordered_data() const
Definition matrix_assembly_data.hpp:140
The Ginkgo namespace.
Definition abstract_factory.hpp:20
constexpr T zero()
Returns the additive identity for T.
Definition math.hpp:626
std::size_t size_type
Integral type used for allocation quantities.
Definition types.hpp:90
A type representing the dimensions of a multidimensional object.
Definition dim.hpp:26
This structure is used as an intermediate data type to store a sparse matrix.
Definition matrix_data.hpp:126
std::vector< nonzero_type > nonzeros
A vector of tuples storing the non-zeros of the matrix.
Definition matrix_data.hpp:453