{"action":"created","issue":{"url":"https://api.github.com/repos/GalSim-developers/GalSim/issues/668","labels_url":"https://api.github.com/repos/GalSim-developers/GalSim/issues/668/labels{/name}","comments_url":"https://api.github.com/repos/GalSim-developers/GalSim/issues/668/comments","events_url":"https://api.github.com/repos/GalSim-developers/GalSim/issues/668/events","html_url":"https://github.com/GalSim-developers/GalSim/pull/668","id":84305395,"number":668,"title":"#661 - WFIRST module accuracy parameters","user":{"login":"rmandelb","id":1454906,"avatar_url":"https://avatars.githubusercontent.com/u/1454906?v=3","gravatar_id":"","url":"https://api.github.com/users/rmandelb","html_url":"https://github.com/rmandelb","followers_url":"https://api.github.com/users/rmandelb/followers","following_url":"https://api.github.com/users/rmandelb/following{/other_user}","gists_url":"https://api.github.com/users/rmandelb/gists{/gist_id}","starred_url":"https://api.github.com/users/rmandelb/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/rmandelb/subscriptions","organizations_url":"https://api.github.com/users/rmandelb/orgs","repos_url":"https://api.github.com/users/rmandelb/repos","events_url":"https://api.github.com/users/rmandelb/events{/privacy}","received_events_url":"https://api.github.com/users/rmandelb/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":9,"created_at":"2015-06-03T01:49:31Z","updated_at":"2015-07-07T02:08:11Z","closed_at":null,"pull_request":{"url":"https://api.github.com/repos/GalSim-developers/GalSim/pulls/668","html_url":"https://github.com/GalSim-developers/GalSim/pull/668","diff_url":"https://github.com/GalSim-developers/GalSim/pull/668.diff","patch_url":"https://github.com/GalSim-developers/GalSim/pull/668.patch"},"body":"This is a short pull request that includes an option to have a higher-fidelity representation of the WFIRST PSFs in Fourier space compared to what you get with the default settings.  See the plots on the issue page for details of how this setting changes the MTF.\r\n\r\nI did not put this into the CHANGELOG because this PR will go into the same release as the initial PR for the WFIRST module, so it's basically a slight improvement of one of the new features in this version of GalSim rather than an improvement on a previous version of GalSim.\r\n\r\nThere is a debatable philosophical point here related to how the WFIRST module is set up:\r\nUnlike OpticalPSF or ChromaticOpticalPSF, the user cannot adjust all the parameters related to the WFIRST optical PSF freely.  Instead, the WFIRST module getPSF() method just has default settings and the new 'high accuracy' settings.  The reason for this choice was that once we are working from the WFIRST pupil plane image, the OpticalPSF kwargs cannot be adjusted freely (i.e., many possible changes to the oversampling or pad factor would result in the routine throwing an exception because the supplied pupil plane image is inadequate in some way).  I think it would take a lot of work to make it possible to adjust the OpticalPSF kwargs completely freely, and I did not feel that it was necessary to do this for an initial version of the WFIRST module.  However, I wanted to flag this design decision, particularly now that we have a 'high accuracy' setting that also isn't adjustable (i.e., it's just a binary choice for default or high accuracy with nothing in between).  Any comments or concerns about this choice?"},"comment":{"url":"https://api.github.com/repos/GalSim-developers/GalSim/issues/comments/119047370","html_url":"https://github.com/GalSim-developers/GalSim/pull/668#issuecomment-119047370","issue_url":"https://api.github.com/repos/GalSim-developers/GalSim/issues/668","id":119047370,"user":{"login":"arunkannawadi","id":5103390,"avatar_url":"https://avatars.githubusercontent.com/u/5103390?v=3","gravatar_id":"","url":"https://api.github.com/users/arunkannawadi","html_url":"https://github.com/arunkannawadi","followers_url":"https://api.github.com/users/arunkannawadi/followers","following_url":"https://api.github.com/users/arunkannawadi/following{/other_user}","gists_url":"https://api.github.com/users/arunkannawadi/gists{/gist_id}","starred_url":"https://api.github.com/users/arunkannawadi/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/arunkannawadi/subscriptions","organizations_url":"https://api.github.com/users/arunkannawadi/orgs","repos_url":"https://api.github.com/users/arunkannawadi/repos","events_url":"https://api.github.com/users/arunkannawadi/events{/privacy}","received_events_url":"https://api.github.com/users/arunkannawadi/received_events","type":"User","site_admin":false},"created_at":"2015-07-07T02:08:11Z","updated_at":"2015-07-07T02:08:11Z","body":"Looks good to me.\r\n\r\nAs far as we know for now, such high accuracy is certainly needed to give these images as inputs to IMCOM. Do we know of any other case where these highly accurate PSFs are a necessity? Currently, the docstring only says that such high accuracies may not be needed for many applications. It may be worthwhile to add a line in the docstring saying explicitly that ``high_accuracy = True`` is needed if a PSF dither sequence is to be used by IMCOM or something of that sort?"}}