issues with xspec about sherpa

[DougBurke]

What OS are you using?
What version of sherpa are you using?
How did you install sherpa?

[perischind]

I am using a Mac! The sherpa version is 4.16, and I installed it using the pip install.

[hamogu]

The pip install does not contains XSPEC by itself. You can install XSPEC yourself before and then configure the build to find and connect to your local XSPEC installation before you call pip see https://sherpa.readthedocs.io/en/4.16.0/install.html#build-from-source . It's certainly possible, but it might not be worth the effort.

If you can install from conda, we have a conda channels that has both XSPEC and Sherpa available:

conda create -n sherpaxsepc -c https://cxc.cfa.harvard.edu/conda/ciao -c conda-forge \
  sherpa ciao-contrib python=3.11

or, if you look at Chandra data, you might want to use the full CIAO installation (which comes with Sherpa and XSPEC: https://cxc.cfa.harvard.edu/ciao/threads/ciao_install_conda/

It is also possible to just install the dependencies (in particular XSPEC with conda) and compile the rest of Sherpa yourself: https://sherpa.readthedocs.io/en/4.16.0/developer/index.html#install-from-source-in-conda

What's best depends a bit on what else you need in your environment, but if you want XSPEC, going with conda is certainly the easiest.

[DougBurke]

The XSPEC support requires that you build Sherpa yourself - we don't have a [*] wheel with XSPEC support (for various reasons, a lot to do with XSPEC itself).

So you would have to follow the XSPEC section of

https://sherpa.readthedocs.io/en/4.16.0/install.html#building-from-source

Note that

• we currently don't support XSPEC 12.14.0 (there is a PR to do so but it hasn't been merged),
• building XSPEC and then getting Sherpa to build against it is known to be tricky on macOS.

[*] I would suggest that you install CIAO since this comes with Sherpa and XSPEC support - for that you'd need to follow https://cxc.cfa.harvard.edu/ciao/download/ - I would suggest the conda installation rather than the ciao-install version.

[perischind]

thank you for your suggestions! I will try to instal CIAO and see if that works.

[DougBurke]

I'm going to close this. Hope the CIAO installation goes easily.