# Streamline length

**URL:** <https://community.mrtrix.org/t/streamline-length/369>\
**Category:** Uncategorized\
**Tags:** connectomics\
**Created:** [July 31, 2016, 10:21am UTC](https://community.mrtrix.org/t/streamline-length/369 "2016-07-31T10:21:48Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![rsmith](https://community.mrtrix.org/user_avatar/community.mrtrix.org/rsmith/32/2672_2.png) [@rsmith](https://community.mrtrix.org/u/rsmith)\
**Post date:** [August 2, 2016, 4:23pm UTC](https://community.mrtrix.org/t/streamline-length/369/2 "2016-08-02T16:23:43Z")

</div>

Yep: in the `tck2connectome` [help page](http://mrtrix.readthedocs.io/en/latest/reference/commands/tck2connectome.html), check out the options for the connectivity metric, as well as the `-stat_edge` option (note that the command interface here changed as part of the [last tagged update](https://community.mrtrix.org/t/mrtrix3-version-incremented-to-0-3-15/300/1)).

So, for instance, if you want the mean streamline length in each edge:

- Use `-scale_length`: This makes the contribution of each streamline to the relevant edge equal to the length of that streamline, rather than unity.
- Use `-stat_edge mean`: This takes the value of each edge as the _mean_ of the values contributed by each streamline within that edge, rather than their sum.

“Calculate the lengths, take the mean” = mean length 😛 It’s not as immediately obvious as the old interface, but it’s a lot more flexible.

Have fun!  
Rob

---

_[View the full topic](https://community.mrtrix.org/t/streamline-length/369)._