{"action":"created","issue":{"url":"https://api.github.com/repos/rmjarvis/TreeCorr/issues/39","repository_url":"https://api.github.com/repos/rmjarvis/TreeCorr","labels_url":"https://api.github.com/repos/rmjarvis/TreeCorr/issues/39/labels{/name}","comments_url":"https://api.github.com/repos/rmjarvis/TreeCorr/issues/39/comments","events_url":"https://api.github.com/repos/rmjarvis/TreeCorr/issues/39/events","html_url":"https://github.com/rmjarvis/TreeCorr/issues/39","id":126636989,"number":39,"title":"Maximum separation","user":{"login":"svw26","id":16702076,"avatar_url":"https://avatars.githubusercontent.com/u/16702076?v=3","gravatar_id":"","url":"https://api.github.com/users/svw26","html_url":"https://github.com/svw26","followers_url":"https://api.github.com/users/svw26/followers","following_url":"https://api.github.com/users/svw26/following{/other_user}","gists_url":"https://api.github.com/users/svw26/gists{/gist_id}","starred_url":"https://api.github.com/users/svw26/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/svw26/subscriptions","organizations_url":"https://api.github.com/users/svw26/orgs","repos_url":"https://api.github.com/users/svw26/repos","events_url":"https://api.github.com/users/svw26/events{/privacy}","received_events_url":"https://api.github.com/users/svw26/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":null,"milestone":{"url":"https://api.github.com/repos/rmjarvis/TreeCorr/milestones/4","html_url":"https://github.com/rmjarvis/TreeCorr/milestones/Version%203.3","labels_url":"https://api.github.com/repos/rmjarvis/TreeCorr/milestones/4/labels","id":1663035,"number":4,"title":"Version 3.3","description":"Changes that will be incorporated into version 3.2","creator":{"login":"rmjarvis","id":623887,"avatar_url":"https://avatars.githubusercontent.com/u/623887?v=3","gravatar_id":"","url":"https://api.github.com/users/rmjarvis","html_url":"https://github.com/rmjarvis","followers_url":"https://api.github.com/users/rmjarvis/followers","following_url":"https://api.github.com/users/rmjarvis/following{/other_user}","gists_url":"https://api.github.com/users/rmjarvis/gists{/gist_id}","starred_url":"https://api.github.com/users/rmjarvis/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/rmjarvis/subscriptions","organizations_url":"https://api.github.com/users/rmjarvis/orgs","repos_url":"https://api.github.com/users/rmjarvis/repos","events_url":"https://api.github.com/users/rmjarvis/events{/privacy}","received_events_url":"https://api.github.com/users/rmjarvis/received_events","type":"User","site_admin":false},"open_issues":3,"closed_issues":3,"state":"open","created_at":"2016-03-24T00:50:49Z","updated_at":"2016-04-10T06:38:25Z","due_on":null,"closed_at":null},"comments":3,"created_at":"2016-01-14T11:38:11Z","updated_at":"2016-04-10T06:38:25Z","closed_at":"2016-04-10T06:38:25Z","body":"Hello Mike\r\n\r\nHope you are well, and thank you for making the TreeCorr package publicly available.\r\n\r\nI was wondering whether there is an inbuilt restriction on the maximum value that the parameter max_sep can be(!). This is because I am using an all-sky survey, and so expect that the maximum separation is 180 degrees (i.e. directly-opposite sides of the celestial sphere). However when I use this I find that there is a cut off, in the number of pairs counted, at 128 degrees. Yet there are clearly pairs of objects that satisfy a separation between 128 and 180 degrees. I thought I would test it using a smaller region, defined over the equator from RA=135 deg to RA=225 deg (-20 < Dec/deg <20), setting max_sep to 90 deg. npairs (for the data-points) remains non-zero until 81.4 deg, yet I can pick a pair of objects whose separation is 88.1 deg.\r\n\r\nOut of curiosity, what is the step used to store the ra and dec values in the catalogues for TreeCorr? As I had specified units='deg', I was puzzled that printing each of the cat_data.ra[i] and cat_data.dec[i] values showed that they did not match up to the input ra and dec. Instead, each needed to be scaled up by a factor of just over 57, and there seemed to be a larger offset as RA increased...\r\n\r\nHope to hear from you soon.\r\nMany thanks,\r\nSarah"},"comment":{"url":"https://api.github.com/repos/rmjarvis/TreeCorr/issues/comments/207932237","html_url":"https://github.com/rmjarvis/TreeCorr/issues/39#issuecomment-207932237","issue_url":"https://api.github.com/repos/rmjarvis/TreeCorr/issues/39","id":207932237,"user":{"login":"rmjarvis","id":623887,"avatar_url":"https://avatars.githubusercontent.com/u/623887?v=3","gravatar_id":"","url":"https://api.github.com/users/rmjarvis","html_url":"https://github.com/rmjarvis","followers_url":"https://api.github.com/users/rmjarvis/followers","following_url":"https://api.github.com/users/rmjarvis/following{/other_user}","gists_url":"https://api.github.com/users/rmjarvis/gists{/gist_id}","starred_url":"https://api.github.com/users/rmjarvis/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/rmjarvis/subscriptions","organizations_url":"https://api.github.com/users/rmjarvis/orgs","repos_url":"https://api.github.com/users/rmjarvis/repos","events_url":"https://api.github.com/users/rmjarvis/events{/privacy}","received_events_url":"https://api.github.com/users/rmjarvis/received_events","type":"User","site_admin":false},"created_at":"2016-04-10T06:38:25Z","updated_at":"2016-04-10T06:38:25Z","body":"I made some updates in response to this, which will be included in version 3.3:\r\n\r\n1. All the attributes that have units of distance will be in the requested sep_units throughout, including min_sep, max_sep, logr, meanr, meanlogr.  This seems more intuitive.  The versions that I need in various places to be in radians are now in \"hidden\" attributes like `_min_sep` and `_max_sep`.\r\n2. For the normal spherical geometry case where I use the chord distances for increased speed over doing the trig functions, I now update the distances at the end to be the real great circle angular distances.  i.e. it now does this equation to the `meanr` and `meanlogr` values at the end of the process function:\r\n\r\n    r_GC = 2 * math.asin(0.5 * r_chord)\r\n\r\nto get back to real angles, rather than the weird hybrid thing it used to do.\r\n\r\n3. I also added a new metric called \"Arc\" which does the (slower) trig functions to get real great circle distances all along the way, rather than correct the angles at the end.  For most purposes, you'll probably want to stick with the faster version, but this will let you compare the two methods to see whether the chord method is leading to any inaccuracies for your application.\r\n\r\nPlease reopen if you have any further questions or comments about these changes.  And thanks again for the bug report."}}