# Processing PRError: setPenT4: invalid pen transformation (singular)

**URL:** https://discourse.processing.org/t/processing-prerror-setpent4-invalid-pen-transformation-singular/22595
**Category:** Libraries
**Created:** [July 13, 2020, 8:57pm UTC](https://discourse.processing.org/t/processing-prerror-setpent4-invalid-pen-transformation-singular/22595 "2020-07-13T20:57:59Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![Leo\_Aguiar](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/leo_aguiar/32/18942_2.png) [@Leo\_Aguiar](https://discourse.processing.org/u/Leo_Aguiar)
#### Post date: [July 13, 2020, 8:57pm UTC](https://discourse.processing.org/t/processing-prerror-setpent4-invalid-pen-transformation-singular/22595/1 "2020-07-13T20:57:59Z")

</div>

Hi forum,

I was working on a sketch using the scale() function and a control P5 slider to set one of the values for it. I got the above error when one of the scale parameters was set to zero. I couldn’t find any documentation online about it. I am just curious about what it means.

Thanks for the help.