# get row from itk matrix

**URL:** <https://discourse.itk.org/t/get-row-from-itk-matrix/5071>\
**Category:** Beginner Questions\
**Tags:** vnl\
**Created:** [June 8, 2022, 4:55pm UTC](https://discourse.itk.org/t/get-row-from-itk-matrix/5071 "2022-06-08T16:55:46Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![stnava](https://discourse.itk.org/user_avatar/discourse.itk.org/stnava/32/2742_2.png) [@stnava](https://discourse.itk.org/u/stnava)\
**Post date:** [June 8, 2022, 4:55pm UTC](https://discourse.itk.org/t/get-row-from-itk-matrix/5071/1 "2022-06-08T16:55:46Z")

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just trying to update some code for more recent itk version (latest release)

Type definitions:

> <https://github.com/ANTsX/ANTsR/blob/master/src/reorientImage.cpp#L29>

> <https://github.com/ANTsX/ANTsR/blob/master/src/reorientImage.cpp#L44-L46>

> <https://github.com/ANTsX/ANTsR/blob/master/src/reorientImage.cpp#L54-L55>

Things that don’t compile b/c they use old vnl types:

> <https://github.com/ANTsX/ANTsR/blob/master/src/reorientImage.cpp#L56-L57>

> <https://github.com/ANTsX/ANTsR/blob/master/src/reorientImage.cpp#L127>

But - in brief - this is a question of how to replace old vnl operations with whatever is the right way to do wrt recent ITK.

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**Author:** ![dzenanz](https://discourse.itk.org/user_avatar/discourse.itk.org/dzenanz/32/1093_2.png) [@dzenanz](https://discourse.itk.org/u/dzenanz)\
**Post date:** [June 8, 2022, 6:30pm UTC](https://discourse.itk.org/t/get-row-from-itk-matrix/5071/2 "2022-06-08T18:30:54Z")

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Unfortunately, we still use VNL under the hood for Matrix. We want to transition to Eigen, but it is a large refactoring and no one has taken it up so far.