49 lines
1.4 KiB
C++
49 lines
1.4 KiB
C++
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#include "find_zero.h"
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#include "for_each.h"
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#include "any.h"
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template <typename AType, typename DerivedI>
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IGL_INLINE void igl::find_zero(
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const Eigen::SparseMatrix<AType> & A,
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const int dim,
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Eigen::PlainObjectBase<DerivedI> & I)
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{
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assert((dim == 1 || dim == 2) && "dim must be 2 or 1");
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// Get size of input
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int m = A.rows();
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int n = A.cols();
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// I starts by containing guess where 0 might be
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I = DerivedI::Zero(dim==1?n:m);
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Eigen::Array<bool,Eigen::Dynamic,1> found =
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Eigen::Array<bool,Eigen::Dynamic,1>::Zero(dim==1?n:m);
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const auto func = [&I,&found,&dim](int i, int j, const int v)
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{
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if(dim == 2)
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{
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std::swap(i,j);
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}
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// Coded as if dim == 1, assuming swap for dim == 2
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// Have we already found a zero?
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if(!found(j))
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{
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if(I(j) != i || v == 0)
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{
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// either there was an implicit zero between the last element and this
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// one, or this one is zero
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found(j) = true;
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}else
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{
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// If not found, then guess that next element will be zero
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I(j) = I(j)+1;
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}
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}
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};
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for_each(A,func);
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}
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#ifdef IGL_STATIC_LIBRARY
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// Explicit template instantiation
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// generated by autoexplicit.sh
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template void igl::find_zero<bool, Eigen::Matrix<int, -1, 1, 0, -1, 1> >(Eigen::SparseMatrix<bool, 0, int> const&, int, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, 1, 0, -1, 1> >&);
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#endif
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