# Upgrade from 413 to 512 and vnl

**URL:** https://discourse.itk.org/t/upgrade-from-413-to-512-and-vnl/4370
**Category:** Engineering
**Created:** [August 26, 2021, 2:53pm UTC](https://discourse.itk.org/t/upgrade-from-413-to-512-and-vnl/4370 "2021-08-26T14:53:12Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![rfrank](https://discourse.itk.org/user_avatar/discourse.itk.org/rfrank/32/2977_2.png) [@rfrank](https://discourse.itk.org/u/rfrank)
#### Post date: [August 26, 2021, 2:53pm UTC](https://discourse.itk.org/t/upgrade-from-413-to-512-and-vnl/4370/1 "2021-08-26T14:53:12Z")

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I’m trying to upgrade an existing project that uses vnl directly for some matrix computations.

for instance

```auto
vnl_vector_fixed<float, 4> temp;
loat ctr4[4] = {(float) ctr[0],(float)ctr[1],(float)ctr[2],1.0f };
temp.set(ctr4);
vnl_float_4x4 inv = vnl_matrix_inverse<float>(volumeMatrixVNL);

vnl_vector_fixed<float, 4> result = inv * temp;

```

no longer compiles.

Is there a list of changes for vnl that would help me update my code?

Thanks

Rick

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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: [August 26, 2021, 3:02pm UTC](https://discourse.itk.org/t/upgrade-from-413-to-512-and-vnl/4370/2 "2021-08-26T15:02:11Z")

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I guess you could look at the [upstream repository](https://github.com/vxl/vxl/tree/master/core/vnl) for changes.

@hjmjohnson, is there something like a migration guide for VNL changes done recently-ish?

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<div class="post-metadata">

### Author: ![hjmjohnson](https://discourse.itk.org/user_avatar/discourse.itk.org/hjmjohnson/32/23_2.png) [@hjmjohnson](https://discourse.itk.org/u/hjmjohnson)
#### Post date: [August 26, 2021, 4:35pm UTC](https://discourse.itk.org/t/upgrade-from-413-to-512-and-vnl/4370/3 "2021-08-26T16:35:49Z")

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The best migration guide for vnl is the ITK migration guide and scripts.

Hans

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<div class="post-metadata">

### 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: [August 26, 2021, 8:10pm UTC](https://discourse.itk.org/t/upgrade-from-413-to-512-and-vnl/4370/4 "2021-08-26T20:10:36Z")

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I just took a look at the migration guide. There is nothing specific for handling changes in VNL. [Scripts](https://github.com/InsightSoftwareConsortium/ITK/blob/master/Documentation/ITK5MigrationGuide.md#update-scripts) could be looked at. Here is a [list](https://github.com/InsightSoftwareConsortium/ITK/search?o=desc&q=vnl_matrix_fixed&s=committer-date&type=commits) of ITK commits mentioning `vnl_matrix_fixed`. There are no mentions of `vnl_vector_fixed`.