{"action":"created","issue":{"url":"https://api.github.com/repos/chebfun/chebfun/issues/1479","labels_url":"https://api.github.com/repos/chebfun/chebfun/issues/1479/labels{/name}","comments_url":"https://api.github.com/repos/chebfun/chebfun/issues/1479/comments","events_url":"https://api.github.com/repos/chebfun/chebfun/issues/1479/events","html_url":"https://github.com/chebfun/chebfun/issues/1479","id":73898651,"number":1479,"title":"Is the .vscale needed in chebtech objects?","user":{"login":"nickhale","id":2035010,"avatar_url":"https://avatars.githubusercontent.com/u/2035010?v=3","gravatar_id":"","url":"https://api.github.com/users/nickhale","html_url":"https://github.com/nickhale","followers_url":"https://api.github.com/users/nickhale/followers","following_url":"https://api.github.com/users/nickhale/following{/other_user}","gists_url":"https://api.github.com/users/nickhale/gists{/gist_id}","starred_url":"https://api.github.com/users/nickhale/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/nickhale/subscriptions","organizations_url":"https://api.github.com/users/nickhale/orgs","repos_url":"https://api.github.com/users/nickhale/repos","events_url":"https://api.github.com/users/nickhale/events{/privacy}","received_events_url":"https://api.github.com/users/nickhale/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/chebfun/chebfun/labels/enhancement","name":"enhancement","color":"84b6eb"},{"url":"https://api.github.com/repos/chebfun/chebfun/labels/question","name":"question","color":"cc317c"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":6,"created_at":"2015-05-07T08:37:59Z","updated_at":"2015-05-18T10:03:04Z","closed_at":null,"body":"Since it seems the `.epslevel` property of `chebtech` objects is about to go the way of the Dodo, should we also consider scrapping the `.vscale` field? \r\n\r\nIn terms of efficiency, I imagine around 50% of the time we will lose by having to compute the same vscale more than once, and the other 50% we will save by having not computed it at all.\r\n\r\nIn terms of the code, it would almost certainly make things simpler: `vscale()` would become a method rather than a property and only called when the vertical scale is required. Strictly speaking, the vscale can always be recovered from the `.coeffs`, so storing it is a duplication of information.\r\n\r\nI think the only reason we _have_ a `.vscale` currently is a hang-over from v4, where it represented something other than the current magnitude of the chebfun."},"comment":{"url":"https://api.github.com/repos/chebfun/chebfun/issues/comments/103004071","html_url":"https://github.com/chebfun/chebfun/issues/1479#issuecomment-103004071","issue_url":"https://api.github.com/repos/chebfun/chebfun/issues/1479","id":103004071,"user":{"login":"aaustin141","id":3380006,"avatar_url":"https://avatars.githubusercontent.com/u/3380006?v=3","gravatar_id":"","url":"https://api.github.com/users/aaustin141","html_url":"https://github.com/aaustin141","followers_url":"https://api.github.com/users/aaustin141/followers","following_url":"https://api.github.com/users/aaustin141/following{/other_user}","gists_url":"https://api.github.com/users/aaustin141/gists{/gist_id}","starred_url":"https://api.github.com/users/aaustin141/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/aaustin141/subscriptions","organizations_url":"https://api.github.com/users/aaustin141/orgs","repos_url":"https://api.github.com/users/aaustin141/repos","events_url":"https://api.github.com/users/aaustin141/events{/privacy}","received_events_url":"https://api.github.com/users/aaustin141/received_events","type":"User","site_admin":false},"created_at":"2015-05-18T10:03:04Z","updated_at":"2015-05-18T10:03:04Z","body":">> On the other hand, vscale is probably the most frequently requested property of a tech, so we should measure some experimental timings first before we commit to doing this.\r\n\r\n> But since accessing properties is so slow in MATLAB, we might actually _gain_ from this..\r\n\r\nI'm not contradicting that; to the contrary, I think this is probably true.  I'm just saying that we should measure to be sure."}}