Reinhold, Right, only Mapnik 2 has improved support for handling unique projections when the data is not in that same projection.
Mapnik 2 has improved this situation greatly, notably r2784, and overall the work is inventoried at http://trac.mapnik.org/wiki/BoundsClipping. For reference Mapnik 0.7.1 was cut from r1747. Dane On Jul 25, 2011, at 5:51 AM, Reinhold Klatt wrote: > Hi Dane, > > Thanks for your help. I missunderstood something. I thought that mapnik > 0.7.1 was able to handle the conic projections. > I have to setup a separate system to run my project with mapnik2. > I will report about my expirinces;) > > Reinhold > > > On 21.07.2011 23:22 Uhr, "Dane Springmeyer" <[email protected]> wrote: > >> Reinhold, >> >> I just ran through your test script and confirmed that I get nice output for >> all the projections listed with Mapnik2 (trunk) >> >> However, the script needs to use mapnik.ProjTransform to handle forwarding >> the >> bbox that is used, otherwise a bogus bbox can be sent to mapnik (and of >> course >> that would lead to a blank map). >> >> I tested with an osm stylesheet referencing data imported into postgres in >> spherical mercator projection. >> >> Fixed up script is here: https://gist.github.com/1098240 >> >> Dane >> >> On Jul 21, 2011, at 1:10 PM, Dane Springmeyer wrote: >> >>> Reinhold, >>> >>> Artem and I just connected on this via skype. We have some fixes for this >>> issue in Mapnik2 (current trunk) and are *not* planning on backporting them >>> to 0.7.x. >>> >>> Are you able to upgrade to the development version of Mapnik? >>> >>> Dane >>> >>> On Jul 21, 2011, at 7:52 AM, Reinhold Klatt wrote: >>> >>>> >>>> ------ Forwarded Message >>>> From: Reinhold Klatt <[email protected]> >>>> Date: Thu, 21 Jul 2011 14:41:22 +0200 >>>> To: Artem Pavlenko <[email protected]> >>>> Conversation: [Mapnik-users] Mapnik and conic projectionsP >>>> Subject: Re: [Mapnik-users] Mapnik and conic projectionsP >>>> >>>> Hi Artem, >>>> >>>> I'm using the version 0.7.1 from mapnik.org >>>> >>>> Reinhold >>>> >>>> >>>> On 21.07.2011 14:23 Uhr, "Artem Pavlenko" <[email protected]> wrote: >>>> >>>>> Which version of Mapnik are you using? >>>>> Artem >>>>> >>>>> On 21 July 2011 11:42, Reinhold Klatt <[email protected]> wrote: >>>>>> Hi all, >>>>>> I'm trying to render maps in a conic projection. The problem is, that i >>>>>> get >>>>>> a blank image as result. >>>>>> If I generate in mercator or latlon there is no problem. I get what I >>>>>> want. >>>>>> But I can't generate anything in a conical projection. >>>>>> I modified a script I found, to test different projections. Does anybody >>>>>> know why it's not working? What's my mistake? Are there parameters that >>>>>> have >>>>>> to be set? >>>>>> >>>>>> Thankyou in advance >>>>>> >>>>>> >>>>>> #!/usr/bin/python >>>>>> import mapnik >>>>>> >>>>>> mapfile = "style9_nodem.xml" >>>>>> >>>>>> projections = { >>>>>> "latlon": "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs", #EPSG:4326 >>>>>> "google": "+proj=merc +lon_0=0 +lat_ts=0 +x_0=0 +y_0=0 +a=6378137 >>>>>> +b=6378137 +units=m +no_defs", # SR-ORG:95 >>>>>> "mercator_world": "+proj=merc +lon_0=0 +k=1 +x_0=0 +y_0=0 +ellps=WGS84 >>>>>> +datum=WGS84 +units=m +no_defs", # SR-ORG:16 >>>>>> "lambert": "+proj=lcc +lat_1=49.83333333333334 +lat_2=51.16666666666666 >>>>>> +lat_0=90 +lon_0=0 +x_0=150000 +y_0=5400000 +ellps=intl +pm=brussels >>>>>> +units=m +no_defs", >>>>>> "albert": "+proj=aea +lat_1=29.83333333333334 +lat_2=45.83333333333334 >>>>>> +lat_0=37.5 +lon_0=-96 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m >>>>>> +no_defs", >>>>>> "pytest": "+proj=lcc +lat_1=45.89893890000052 +lat_2=47.69601440000037 >>>>>> +lat_0=46.8 +lon_0=2.33722917 +x_0=600000 +y_0=200000 +a=6378249.145 >>>>>> +b=6356514.96582849 +pm=2.337229167 +units=m +no_defs", >>>>>> } >>>>>> >>>>>> ll = (8.487, 49.9857, 8.6237, 50.0622) >>>>>> >>>>>> imgx = 1000 >>>>>> imgy = 1000 >>>>>> >>>>>> # Render an image for every projection >>>>>> for projName, projDef in sorted(projections.items()): >>>>>> >>>>>> print "Projection: " + projName >>>>>> >>>>>> # Load the map data >>>>>> m = mapnik.Map(imgx, imgy) >>>>>> mapnik.load_map(m, mapfile) >>>>>> >>>>>> # Override projection defined in osm.xml >>>>>> m.srs = projDef >>>>>> >>>>>> # Calculate projected boundaries >>>>>> prj = mapnik.Projection(projDef) >>>>>> c0 = prj.forward(mapnik.Coord(ll[0], ll[1])) >>>>>> c1 = prj.forward(mapnik.Coord(ll[2], ll[3])) >>>>>> >>>>>> # Apply bounding box >>>>>> bbox = mapnik.Envelope(c0.x, c0.y, c1.x, c1.y) >>>>>> m.zoom_to_box(bbox) >>>>>> >>>>>> # Render image >>>>>> im = mapnik.Image(imgx, imgy) >>>>>> mapnik.render(m, im) >>>>>> view = im.view(0, 0, imgx, imgy) >>>>>> view.save("img/" + projName + ".png", "png256") >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Mapnik-users mailing list >>>>>> [email protected] >>>>>> https://lists.berlios.de/mailman/listinfo/mapnik-users >>>>>> >>>>> >>>> >>>> ------ End of Forwarded Message >>>> >>>> >>>> _______________________________________________ >>>> Mapnik-users mailing list >>>> [email protected] >>>> https://lists.berlios.de/mailman/listinfo/mapnik-users >>> >> >> > > _______________________________________________ Mapnik-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/mapnik-users
