# How to apply this matix in slicer for a modelNode

**URL:** <https://discourse.slicer.org/t/how-to-apply-this-matix-in-slicer-for-a-modelnode/26025>\
**Category:** Support\
**Created:** [November 2, 2022, 9:35am UTC](https://discourse.slicer.org/t/how-to-apply-this-matix-in-slicer-for-a-modelnode/26025 "2022-11-02T09:35:58Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![timeanddoctor](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/timeanddoctor/32/5839_2.png) [@timeanddoctor](https://discourse.slicer.org/u/timeanddoctor)\
**Post date:** [November 2, 2022, 9:35am UTC](https://discourse.slicer.org/t/how-to-apply-this-matix-in-slicer-for-a-modelnode/26025/1 "2022-11-02T09:35:58Z")

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np.Mtrix(Transform4\*4): K, R  
position(x,y,z): X(position), Y(target)

(R[2,:]_X)Y=KR_X

Can I change upper equation to such format : Y=Mat\*X. So if X is a Node , I could use it in slicer.  
Thanks

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<div class="post-metadata">

**Author:** ![timeanddoctor](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/timeanddoctor/32/5839_2.png) [@timeanddoctor](https://discourse.slicer.org/u/timeanddoctor)\
**Post date:** [November 2, 2022, 9:36am UTC](https://discourse.slicer.org/t/how-to-apply-this-matix-in-slicer-for-a-modelnode/26025/2 "2022-11-02T09:36:54Z")

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![未命名_副本](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/e/5/e5b7c81da7934c3e9f8770978953434ab62f6778.jpeg)

Can I change the equation to such format : Y=Mat\*X.