dust3d/third_party/libigl/include/igl/nchoosek.h

47 lines
1.2 KiB
C++

// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2015 Olga Diamanti, Alec Jacobson
//
// 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_NCHOOSEK
#define IGL_NCHOOSEK
#include "igl_inline.h"
#include "deprecated.h"
#include <vector>
#include <Eigen/Core>
namespace igl
{
// NCHOOSEK Like matlab's nchoosek.
//
// Inputs:
// n total number elements
// k size of sub-set to consider
// Returns number of k-size combinations out of the set [1,...,n]
IGL_INLINE double nchoosek(const int n, const int k);
//
// Inputs:
// V n-long vector of elements
// k size of sub-set to consider
// Outputs:
// U nchoosek by k long matrix where each row is a unique k-size
// combination
template < typename DerivedV, typename DerivedU>
IGL_INLINE void nchoosek(
const Eigen::MatrixBase<DerivedV> & V,
const int k,
Eigen::PlainObjectBase<DerivedU> & U);
}
#ifndef IGL_STATIC_LIBRARY
#include "nchoosek.cpp"
#endif
#endif /* defined(IGL_NCHOOSEK) */