# Large position values for TF

**URL:** <https://forum.ubiquityrobotics.com/t/large-position-values-for-tf/453>\
**Category:** Uncategorized\
**Created:** [January 31, 2020, 9:04am UTC](https://forum.ubiquityrobotics.com/t/large-position-values-for-tf/453 "2020-01-31T09:04:34Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![cnboonhan94](https://forum.ubiquityrobotics.com/letter_avatar_proxy/v4/letter/c/13edae/32.png) [@cnboonhan94](https://forum.ubiquityrobotics.com/u/cnboonhan94)\
**Post date:** [January 31, 2020, 9:04am UTC](https://forum.ubiquityrobotics.com/t/large-position-values-for-tf/453/1 "2020-01-31T09:04:34Z")

</div>

Hello there,

I come across some interesting behaviour when running amcl on the Magni:

```auto
transforms: 
  - 
    header: 
      seq: 0
      stamp: 
        secs: 1580460145
        nsecs: 985165083
      frame_id: "map"
    child_frame_id: "odom"
    transform: 
      translation: 
        x: -1.45231581031e+184
        y: 1.52068698436e+199
        z: 0.0
      rotation: 
        x: -0.0
        y: -0.0
        z: 1.28566101737e-07
        w: 1.0
---
transforms: 
  - 
    header: 
      seq: 0
      stamp: 
        secs: 1580460146
        nsecs: 28979768
      frame_id: "map"
    child_frame_id: "odom"
    transform: 
      translation: 
        x: -1.45231581031e+184
        y: 1.52068698436e+199
        z: 0.0
      rotation: 
        x: -0.0
        y: -0.0
        z: 1.28566101737e-07
        w: 1.0

```

where the position values are yuge. I’m not sure how to reproduce this and it is quite rare, but a cold start seems to solve the problem. This causes an error when running rviz:

```auto
rviz: /build/ogre-1.9-B6QkmW/ogre-1.9-1.9.0+dfsg1/OgreMain/src/OgreNode.cpp:630: virtual void Ogre::Node::setScale(const Ogre::Vector3&): Assertion `!inScale.isNaN() && "Invali
d vector supplied as parameter"' failed.                                                                                                                                        
Aborted (core dumped) 

```

due to the large position values. I am currently using the Pi4 image.

---

<div class="post-metadata">

**Author:** ![mjstn2011](https://forum.ubiquityrobotics.com/user_avatar/forum.ubiquityrobotics.com/mjstn2011/32/30_2.png) [@mjstn2011](https://forum.ubiquityrobotics.com/u/mjstn2011)\
**Post date:** [February 1, 2020, 7:33pm UTC](https://forum.ubiquityrobotics.com/t/large-position-values-for-tf/453/2 "2020-02-01T19:33:21Z")

</div>

Please supply info on the revisions of code in use.

- The Pi4 is a work in progress and not fully released at this time although this may not be related to use of Pi4 is my thought.

- Are you using our fiducials repository and if so are you using current code or a git branch.

- What launch file are you using? Your own or one from our github or image?