47 lines
1.3 KiB
C++
47 lines
1.3 KiB
C++
|
// This file is part of libigl, a simple c++ geometry processing library.
|
||
|
|
//
|
||
|
|
// Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
|
||
|
|
//
|
||
|
|
// This Source Code Form is subject to the terms of the Mozilla Public License
|
||
|
|
// v. 2.0. If a copy of the MPL was not distributed with this file, You can
|
||
|
|
// obtain one at http://mozilla.org/MPL/2.0/.
|
||
|
|
#include "group_sum_matrix.h"
|
||
|
|
|
||
|
|
template <typename T>
|
||
|
|
IGL_INLINE void igl::group_sum_matrix(
|
||
|
|
const Eigen::Matrix<int,Eigen::Dynamic,1> & G,
|
||
|
|
const int k,
|
||
|
|
Eigen::SparseMatrix<T>& A)
|
||
|
|
{
|
||
|
|
// number of vertices
|
||
|
|
int n = G.rows();
|
||
|
|
assert(k > G.maxCoeff());
|
||
|
|
|
||
|
|
A.resize(k,n);
|
||
|
|
|
||
|
|
// builds A such that A(i,j) = 1 where i corresponds to group i and j
|
||
|
|
// corresponds to vertex j
|
||
|
|
|
||
|
|
// Loop over vertices
|
||
|
|
for(int j = 0;j<n;j++)
|
||
|
|
{
|
||
|
|
A.insert(G(j),j) = 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
A.makeCompressed();
|
||
|
|
}
|
||
|
|
|
||
|
|
template <typename T>
|
||
|
|
IGL_INLINE void igl::group_sum_matrix(
|
||
|
|
const Eigen::Matrix<int,Eigen::Dynamic,1> & G,
|
||
|
|
Eigen::SparseMatrix<T>& A)
|
||
|
|
{
|
||
|
|
return group_sum_matrix(G,G.maxCoeff()+1,A);
|
||
|
|
}
|
||
|
|
|
||
|
|
#ifdef IGL_STATIC_LIBRARY
|
||
|
|
// Explicit template instantiation
|
||
|
|
template void igl::group_sum_matrix<double>(Eigen::Matrix<int, -1, 1, 0, -1, 1> const&, int, Eigen::SparseMatrix<double, 0, int>&);
|
||
|
|
template void igl::group_sum_matrix<double>(Eigen::Matrix<int, -1, 1, 0, -1, 1> const&, Eigen::SparseMatrix<double, 0, int>&);
|
||
|
|
#endif
|