Mike Jarvis

Are you waiting on me for anything here? I thought you still had some more comments to address, so I was waiting for that to be done. But if it...

Fixed in #446

This will be easier in GalSim 2.5. I have a solution in progress. The gist is that we will be able to add an `initial_image` input item that reads in...

https://github.com/GalSim-developers/GalSim/pull/1237

I think the convention in those instance catalog *was* the old PhoSim convention. So when reading an instance catalog, we want to switch it. The convention in the new SkyCatalogs...

I don't think optional parameters should be getting set to None. They should be omitted from the kwargs. Are you sure it's getting set to None somehow?

I added a line `assert flip_g2 is not None`, and all the unit tests pass. So if it is being set to None somewhere, it's not in a code path...

FWIW, I think we should keep the default =True for instance catalogs. I think it's unlikely that anyone will start making instance catalogs with the galsim sign convention. Pretty much...

> Having a simple text file input is really important for non-expert who want to try things themselves and who want to make small scenes. There are more user-friendly ways...

GalSim demo 4 shows how to use an input catalog for all parameters. That can be either text or fits as preferred. https://github.com/GalSim-developers/GalSim/blob/releases/2.4/examples/demo4.yaml