Change length units to m?

Hi,

The OpenMC documentation suggests that length units could be specified in the non-default unit of meters:

Unless specified otherwise, all length quantities are assumed to be in units of centimeters

but I’m not sure how to achieve this. I have a python module with geometry info in terms of meters that I’d like to be able to import without having to scale everything. How do I change the length units in OpenMC?

Thanks!

-April

Hi April!

The “Unless specified otherwise” really means “when you’re reading this documentation, any length quantities are in [cm] unless the docs say otherwise” rather than “OpenMC uses [cm] unless you say otherwise.” Sorry for the ambiguity! (a pull request changing the wording is welcome if you feel strongly). Right now everything has to be in [cm] so unfortunately there’s no way as a user to tell OpenMC to use different units. One day maybe… For now, I would suggest just making a variable in your Python module, meter = 100.0, and then using that whenever you specify lengths. It’ll be a little verbose but very clear to anyone reading your module.

Best,
Paul

Ohh, okay, got it! Thanks :slight_smile: