# Transformations and ras cordinates

**URL:** <https://discourse.slicer.org/t/transformations-and-ras-cordinates/4539>\
**Category:** Support\
**Created:** [October 26, 2018, 7:17am UTC](https://discourse.slicer.org/t/transformations-and-ras-cordinates/4539 "2018-10-26T07:17:46Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Melanie](https://avatars.discourse-cdn.com/v4/letter/m/35a633/32.png) [@Melanie](https://discourse.slicer.org/u/Melanie)\
**Post date:** [October 26, 2018, 7:17am UTC](https://discourse.slicer.org/t/transformations-and-ras-cordinates/4539/1 "2018-10-26T07:17:46Z")

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Hi,  
I am tracking movement using 4d ct. When I harden the transform in order to copy the RAS coordinates to clip board, I get different reading to not doing so. Eg: My fiducial marker X would give RAS values after transforming for each frame say, abc, a1b1 ca, etc. But when I harden one frame, the next frame gives different set of values , say instead of a1b1 c1 I am expecting it would give a11b11 c11- ( I apply transform again to the subsequent frame because the previous frame is hardened. If not vavule does not change at all) So my question is which one is correct , please. Without hardening I cannot copy my values to clip board, I used to copy each number separately without hardening- but becomes tedious when you exceed some 20 frames. I have no knowledge in python to work this out.

Thanks a lot