{"action":"created","issue":{"url":"https://api.github.com/repos/mtennekes/tmap/issues/24","labels_url":"https://api.github.com/repos/mtennekes/tmap/issues/24/labels{/name}","comments_url":"https://api.github.com/repos/mtennekes/tmap/issues/24/comments","events_url":"https://api.github.com/repos/mtennekes/tmap/issues/24/events","html_url":"https://github.com/mtennekes/tmap/issues/24","id":95435815,"number":24,"title":"dot maps?","user":{"login":"joelgombin","id":1918735,"avatar_url":"https://avatars.githubusercontent.com/u/1918735?v=3","gravatar_id":"","url":"https://api.github.com/users/joelgombin","html_url":"https://github.com/joelgombin","followers_url":"https://api.github.com/users/joelgombin/followers","following_url":"https://api.github.com/users/joelgombin/following{/other_user}","gists_url":"https://api.github.com/users/joelgombin/gists{/gist_id}","starred_url":"https://api.github.com/users/joelgombin/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/joelgombin/subscriptions","organizations_url":"https://api.github.com/users/joelgombin/orgs","repos_url":"https://api.github.com/users/joelgombin/repos","events_url":"https://api.github.com/users/joelgombin/events{/privacy}","received_events_url":"https://api.github.com/users/joelgombin/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":6,"created_at":"2015-07-16T13:42:31Z","updated_at":"2015-07-22T20:42:53Z","closed_at":null,"body":"See http://www.washingtonpost.com/blogs/wonkblog/wp/2015/07/16/how-railroads-highways-and-other-man-made-lines-racially-divide-americas-cities/ for example"},"comment":{"url":"https://api.github.com/repos/mtennekes/tmap/issues/comments/123855910","html_url":"https://github.com/mtennekes/tmap/issues/24#issuecomment-123855910","issue_url":"https://api.github.com/repos/mtennekes/tmap/issues/24","id":123855910,"user":{"login":"mtennekes","id":2444081,"avatar_url":"https://avatars.githubusercontent.com/u/2444081?v=3","gravatar_id":"","url":"https://api.github.com/users/mtennekes","html_url":"https://github.com/mtennekes","followers_url":"https://api.github.com/users/mtennekes/followers","following_url":"https://api.github.com/users/mtennekes/following{/other_user}","gists_url":"https://api.github.com/users/mtennekes/gists{/gist_id}","starred_url":"https://api.github.com/users/mtennekes/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mtennekes/subscriptions","organizations_url":"https://api.github.com/users/mtennekes/orgs","repos_url":"https://api.github.com/users/mtennekes/repos","events_url":"https://api.github.com/users/mtennekes/events{/privacy}","received_events_url":"https://api.github.com/users/mtennekes/received_events","type":"User","site_admin":false},"created_at":"2015-07-22T20:42:53Z","updated_at":"2015-07-22T20:42:53Z","body":"We'll have to sample anyway if there are over 1M data points, since the resolution is a bottleneck.\r\nIt may be a blessing in disguise, because it prevents serious running time/memory/occlusion issues.\r\nI mean, `tmap` is probably equivalent to `ggplot2` regarding running time. Did any of you ever managed to plot 300M objects with `ggplot2`?\r\n\r\nMaybe we could add a layer-function `tm_dots`, which is a simplified/faster version of `tm_bubbles`. \r\nSize isn't an aesthetic, only color. \r\n\r\nIn order to make it fast, we could add an extra argument `N`, an upper bound to the number of plotted dots, sampled with `spsample`.\r\n\r\nAnother route that may be very promising is to use `raster`, which can handle very large objects. A procedure might be:\r\n* Create a `Raster` object with dimensions that are matched to the required resolution.\r\n* Bin the spatial points to raster cells. Raster cells without spatial points have the default `NA` values, and are hence transparent.\r\n* Convert the `Raster` back to a `SpatialPointsDataFrame` in order to draw dots. (Only needed if they are larger than pixels.)"}}