Access a column of a matrix as a vector in Eigen

Question

How can I access a single vector from a matrix?

For example: Is there a way to extract a vector using something like A(i) for a matrix Eigen::MatrixXf A(10,10) that returns an Eigen::VectorXf A(10)?

If you have found the answer please add the answer as an answer below so others can benefit from it :) — Jim Jeffries, Mar 01 '12 at 09:24

score 60 · Accepted Answer · answered Mar 01 '12 at 17:26

60

Found in the documentation :/ The way to access a single column is .col(i), and similarly for row, its .row(i). Also of interest is .block<>.

answered Mar 01 '12 at 17:26

R.J.

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Here: https://eigen.tuxfamily.org/dox/group__TutorialBlockOperations.html – zardosht Jun 12 '20 at 16:49

Access a column of a matrix as a vector in Eigen

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