{"action":"created","issue":{"url":"https://api.github.com/repos/dcjones/Gadfly.jl/issues/293","labels_url":"https://api.github.com/repos/dcjones/Gadfly.jl/issues/293/labels{/name}","comments_url":"https://api.github.com/repos/dcjones/Gadfly.jl/issues/293/comments","events_url":"https://api.github.com/repos/dcjones/Gadfly.jl/issues/293/events","html_url":"https://github.com/dcjones/Gadfly.jl/issues/293","id":33292450,"number":293,"title":"Contour plots?","user":{"login":"tlycken","id":1550920,"avatar_url":"https://avatars.githubusercontent.com/u/1550920?v=3","gravatar_id":"","url":"https://api.github.com/users/tlycken","html_url":"https://github.com/tlycken","followers_url":"https://api.github.com/users/tlycken/followers","following_url":"https://api.github.com/users/tlycken/following{/other_user}","gists_url":"https://api.github.com/users/tlycken/gists{/gist_id}","starred_url":"https://api.github.com/users/tlycken/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/tlycken/subscriptions","organizations_url":"https://api.github.com/users/tlycken/orgs","repos_url":"https://api.github.com/users/tlycken/repos","events_url":"https://api.github.com/users/tlycken/events{/privacy}","received_events_url":"https://api.github.com/users/tlycken/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/dcjones/Gadfly.jl/labels/enhancement","name":"enhancement","color":"84b6eb"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":45,"created_at":"2014-05-12T09:29:41Z","updated_at":"2015-10-15T14:40:15Z","closed_at":null,"body":"If I understand correctly, Gadfly currently focuses on 2D plotting mainly because drawing in 3D is a quite different endeavor. However, there are several types of plots that visualize 3D data on a 2D surface, such as [contour plots](http://en.wikipedia.org/wiki/Contour_plot) and color-coded projections like MATLAB's `imagesc`, that I think would constitute a nice addition to the library.\r\n\r\nAre there any plans on adding functionality for such plots to Gadfly, in the near or distant future?\r\n\r\nFor contour plots, for example, calculating where to draw the contour lines is quite involved (see e.g. [this description](http://www.debrief.info/tutorial/contouring_algorithm.html) for a simple overview - one might want to do something even more sophisticated about edge cases) but once the line segments have been identified it should be straight-forward to hook into the existing back-ends to do the actual drawing of colored lines. I guess one could do similar things to create colored projections à la `imagesc`."},"comment":{"url":"https://api.github.com/repos/dcjones/Gadfly.jl/issues/comments/148406896","html_url":"https://github.com/dcjones/Gadfly.jl/issues/293#issuecomment-148406896","issue_url":"https://api.github.com/repos/dcjones/Gadfly.jl/issues/293","id":148406896,"user":{"login":"tlycken","id":1550920,"avatar_url":"https://avatars.githubusercontent.com/u/1550920?v=3","gravatar_id":"","url":"https://api.github.com/users/tlycken","html_url":"https://github.com/tlycken","followers_url":"https://api.github.com/users/tlycken/followers","following_url":"https://api.github.com/users/tlycken/following{/other_user}","gists_url":"https://api.github.com/users/tlycken/gists{/gist_id}","starred_url":"https://api.github.com/users/tlycken/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/tlycken/subscriptions","organizations_url":"https://api.github.com/users/tlycken/orgs","repos_url":"https://api.github.com/users/tlycken/repos","events_url":"https://api.github.com/users/tlycken/events{/privacy}","received_events_url":"https://api.github.com/users/tlycken/received_events","type":"User","site_admin":false},"created_at":"2015-10-15T14:40:15Z","updated_at":"2015-10-15T14:40:15Z","body":"@tbreloff The underlying contour calculations are done by [Contour.jl](http://github.com/tlycken/Contourl.jl), which currently only supports (rectangularly) gridded data. I see no reason why it shouldn't *work* with sparse matrices, but it will probably be very inefficient - there are no optimizations in place for it, so the algorithm will index into each location - even the zero ones - at least once.\r\n\r\nRegarding the other features, I don't think there's any work going on to support them at the moment, but @darwindarak probably knows better; I know I've seen requests for support of layering contours (earlier in this thread, for example) but I don't know if anything has actually happened."}}