rhdtownsend / msg

Multidimensional Spectral Grids
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importing an existing grid with ascii_to_specint? #21

Open cosmicbabs opened 8 months ago

cosmicbabs commented 8 months ago

Hi Rich and Aaron,

Yesterday, I found MSG, which is precisely what I was looking for! I want to test a few grids of synthetic spectra, and I need to interpolate them without losing the flux information (something that I still need to figure out with Starfish, for example, but I think it is impossible).

I just did the Python Walkthrough, and everything worked out fine. I'm downloading the Solar-alpha Göttingen Grids from the website to test them.

I want to import the BTSettl models with their different 'flavors.' I read the documentation and saw the tools to do it. However, I'm new to Python (used to do all in IDL), and I'm trying to figure out how to call the ascii_to_specint function to include the labels, etc, to follow the Importing Data instructions. Could you please help me with that?

The original site of the BTSettl models is not working anymore (I guess after the passing of France Allard the website got removed) but VOSA/VO has them in ascii and VOTable formats, so I plan to use those.

Thanks! Babs

rhdtownsend commented 6 months ago

Hi Babs --

Thanks for your report -- only just saw it today (for some reason I don't get github issue notifications for MSG; must fix).

I'm happy to help you get up and running with ascii_to_specinit. Here's an example invocation:

$MSG_DIR/bin/ascii_to_specint spectrum.txt A erg/cm^2/s/A specint.h5 Teff 2300 logg 4.0

This will read data from the ASCII file spectrum.txt, which is assumed to be a two-column sequence of (wavelength,flux) values. The wavelength is interpreted as having units of Angstrom, and the flux as having units of erg/cm^2/s/A (currently, only these units are supported -- but I will add other options as they are needed, so let me know if BTSettl uses other units). The output specint file is specint.h5, and it will be written with a pair of labels: Teff=2300 and logg=4.0. Any number of additional label name / label value pairs can be added on the command line.

Does this help get the ball rolling?

Best wishes,

Rich