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c++matlabmatrixsliceeigen

Eigen boolean array slicing

In MATLAB it is common to slice out values that satisfy some condition from a matrix/array (called logical indexing).

vec = [1 2 3 4 5];
condition = vec > 3;
vec(condition) = 3;

How do I do this in Eigen? So far I have:

Eigen::Matrix<bool, 1, 5> condition = vec.array() > 3;
Solution

  • As pointed out in the answer to an similar question here: Submatrices and indices using Eigen, libigl adds this functionality to Eigen.

    igl::slice(A,indices,B);

    Is equivalent to

    B = A(indices)