46 lines
1.4 KiB
C
46 lines
1.4 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/.
|
||
|
|
#ifndef IGL_GROUP_SUM_MATRIX_H
|
||
|
|
#define IGL_GROUP_SUM_MATRIX_H
|
||
|
|
#include "igl_inline.h"
|
||
|
|
|
||
|
|
#include <Eigen/Dense>
|
||
|
|
#include <Eigen/Sparse>
|
||
|
|
|
||
|
|
namespace igl
|
||
|
|
{
|
||
|
|
// GROUP_SUM_MATRIX Builds a matrix A such that A*V computes the sum of
|
||
|
|
// vertices in each group specified by G
|
||
|
|
//
|
||
|
|
// group_sum_matrix(G,k,A);
|
||
|
|
//
|
||
|
|
// Templates:
|
||
|
|
// T should be a eigen sparse matrix primitive type like int or double
|
||
|
|
// Inputs:
|
||
|
|
// G #V list of group indices (0 to k-1) for each vertex, such that vertex i
|
||
|
|
// is assigned to group G(i)
|
||
|
|
// k #groups, good choice is max(G)+1
|
||
|
|
// Outputs:
|
||
|
|
// A #groups by #V sparse matrix such that A*V = group_sums
|
||
|
|
//
|
||
|
|
template <typename T>
|
||
|
|
IGL_INLINE void group_sum_matrix(
|
||
|
|
const Eigen::Matrix<int,Eigen::Dynamic,1> & G,
|
||
|
|
const int k,
|
||
|
|
Eigen::SparseMatrix<T>& A);
|
||
|
|
// Wrapper with k = max(G)+1
|
||
|
|
template <typename T>
|
||
|
|
IGL_INLINE void group_sum_matrix(
|
||
|
|
const Eigen::Matrix<int,Eigen::Dynamic,1> & G,
|
||
|
|
Eigen::SparseMatrix<T>& A);
|
||
|
|
}
|
||
|
|
#ifndef IGL_STATIC_LIBRARY
|
||
|
|
# include "group_sum_matrix.cpp"
|
||
|
|
#endif
|
||
|
|
#endif
|