[yt-dev] Microns & Simulation-Specific Unit Base

[Axel Huebl]

Ha, I oversaw a link in [1] linking to [2].

Ok, so I can just specify my own unit system in user-code with that.
But anyhow, I can't assign it new symbols. Also, do all conversion
factors need to go through CGS?

Also, microns turns out to be
   .in_units("um")
:)


Axel

[2] http://yt-project.org/docs/dev/analyzing/units/unit_systems.html

On 05.01.2017 13:59, Axel Huebl wrote:
> Hi yt-devs!
> 
> I have a quick user-question (sorry) and a devel question:
> 
> First, how to convert to a unit like microns (10^-6 meters) or
> pico-seconds? I can't find an example here [1]. I tried
> 
>   .in_units("mum")
>   .in_units("mu m)
>   .in_units("1.e-6 m")
>   .in_units("microns")
>   .in_units("micro meter")
>   .in_units("micro meters")
>   .in_units("micro m")
>   .in_units("μm")
> 
> and only
>   .in_units("1.e-6 * m")
> 
> does not fail but looks ugly.
> 
> An orthogonal question: in our domain (laser-plasma physics) unit
> systems are scaled by something like the applied laser wavelength or the
> plasma density (and more to make a full set).
> 
> Following again [1] I would implement something like .in_base('plasma')
> or .in_base('laserplasma') but those are not scaled to "fixed" reference
> quantities as the other base systems but are depending on either user input
>   [ length = ("$\lambda_0$", "800 nm"),
>     time   = ("$\omega_\text{pe}^{-1}$", "1.e-15 s"),
>      ...]
> or alternatively scalings the data file already provided. (Ok, the
> symbol is always fixed per "in_base" but the value to scale with needs
> to be provided.)
> 
> Is that already possible or any ideas how we could implement that?
> 
> 
> Thanks,
> Axel
> 
> [1]
> http://yt-project.org/docs/dev/analyzing/units/fields_and_unit_conversion.html#data-selection-and-fields
> 

-- 

Axel Huebl
Phone +49 351 260 3582
https://www.hzdr.de/crp
Computational Radiation Physics
Laser Particle Acceleration Division
Helmholtz-Zentrum Dresden - Rossendorf e.V.

Bautzner Landstrasse 400, 01328 Dresden
POB 510119, D-01314 Dresden
Vorstand: Prof. Dr.Dr.h.c. R. Sauerbrey
          Prof. Dr.Dr.h.c. P. Joehnk
VR 1693 beim Amtsgericht Dresden