Stan Math Library  2.10.0
reverse mode automatic differentiation
csr_to_dense_matrix.hpp
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1 #ifndef STAN_MATH_PRIM_MAT_FUN_CSR_TO_DENSE_MATRIX_HPP
2 #define STAN_MATH_PRIM_MAT_FUN_CSR_TO_DENSE_MATRIX_HPP
3 
10 #include <vector>
11 
12 namespace stan {
13 
14  namespace math {
15 
33  template <typename T>
34  inline Eigen::Matrix<T, Eigen::Dynamic, Eigen::Dynamic>
35  csr_to_dense_matrix(const int& m,
36  const int& n,
37  const Eigen::Matrix<T, Eigen::Dynamic, 1>& w,
38  const std::vector<int>& v,
39  const std::vector<int>& u) {
40  using Eigen::Dynamic;
41  using Eigen::Matrix;
42 
43  check_positive("csr_to_dense_matrix", "m", m);
44  check_positive("csr_to_dense_matrix", "n", n);
45  check_size_match("csr_to_dense_matrix", "m", m, "u", u.size()-1);
46  check_size_match("csr_to_dense_matrix", "w", w.size(), "v", v.size());
47  check_size_match("csr_to_dense_matrix", "u/z",
48  u[m-1] + csr_u_to_z(u, m - 1) - 1,
49  "v", v.size());
50  for (size_t i = 0; i < v.size(); ++i)
51  check_range("csr_to_dense_matrix", "v[]", n, v[i]);
52 
53  Matrix<T, Dynamic, Dynamic> result(m, n);
54  result.setZero();
55  for (int row = 0; row < m; ++row) {
56  int row_end_in_w = (u[row] - stan::error_index::value)
57  + csr_u_to_z(u, row);
58  check_range("csr_to_dense_matrix", "w", w.size(), row_end_in_w);
59  for (int nze = u[row] - stan::error_index::value;
60  nze < row_end_in_w; ++nze) {
61  // row is row index, v[nze] is column index. w[nze] is entry value.
62  check_range("csr_to_dense_matrix", "j", n, v[nze]);
63  result(row, v[nze] - stan::error_index::value) = w(nze);
64  }
65  }
66  return result;
67  }
68  // end of csr_format group
70 
71  }
72 }
73 #endif
int csr_u_to_z(const std::vector< int > &u, int i)
Return the z vector computed from the specified u vector at the index for the z vector.
Definition: csr_u_to_z.hpp:24
Eigen::Matrix< T, Eigen::Dynamic, Eigen::Dynamic > csr_to_dense_matrix(const int &m, const int &n, const Eigen::Matrix< T, Eigen::Dynamic, 1 > &w, const std::vector< int > &v, const std::vector< int > &u)
Construct a dense Eigen matrix from the CSR format components.
bool check_range(const char *function, const char *name, const int max, const int index, const int nested_level, const char *error_msg)
Return true if specified index is within range.
Definition: check_range.hpp:29
Eigen::Matrix< T, 1, Eigen::Dynamic > row(const Eigen::Matrix< T, Eigen::Dynamic, Eigen::Dynamic > &m, size_t i)
Return the specified row of the specified matrix, using start-at-1 indexing.
Definition: row.hpp:25
bool check_positive(const char *function, const char *name, const T_y &y)
Return true if y is positive.
bool check_size_match(const char *function, const char *name_i, T_size1 i, const char *name_j, T_size2 j)
Return true if the provided sizes match.

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