[mapserver-users] Tiger line file and mapserver

[Adam Eskreis]

David, thank you so much for your help, you solved my problem 100%.  I had
no idea mapserver could reproject on the fly! that is so cool.  Anyway,
thanks a lot.

-Adam

On Fri, Nov 5, 2010 at 2:23 PM, Fawcett, David (MPCA) <
David.Fawcett at state.mn.us> wrote:

>  Adam,
>
>
>
> There was a TIGER import into OSM, but many of the ways have been edited
> since the original import.
>
>
>
> From the display standpoint, the spatial reference system (SRS) of the
> input data set is not very important.  It is the output SRS that is
> important.  I think that you will want to set your output projection to
> world Mercator (epsg:900913 or epsg:3785)
> http://spatialreference.org/ref/epsg/3785/
>
>
>
> If you use 900913, make sure that there is an entry in your epsg database
> for it, you may need to add it.
>
>
>
> With MapServer, you can re-project on the fly, so your data doesn’t need to
> be in the output SRS, but you can make your map rendering more efficient by
> pre-projecting the data to the output SRS.
>
>
>
> David.
>
>
>
> *From:* Adam Eskreis [mailto:aeskreis at gmail.com]
> *Sent:* Friday, November 05, 2010 12:12 PM
> *To:* Fawcett, David (MPCA)
> *Cc:* mapserver-users at lists.osgeo.org
> *Subject:* Re: [mapserver-users] Tiger line file and mapserver
>
>
>
> So would that mean that they converted the entire tiger line file to a
> different projection?  I will give that a try.  Thank you for the
> suggestion.
>
> On Fri, Nov 5, 2010 at 1:08 PM, Fawcett, David (MPCA) <
> David.Fawcett at state.mn.us> wrote:
>
> It could be that your data is in a geographic spatial reference system and
> that the OSM tiles are in a World Mercator spatial reference system
> (epsg:900913).
>
>
>
> David.
>
>
>
> *From:* mapserver-users-bounces at lists.osgeo.org [mailto:
> mapserver-users-bounces at lists.osgeo.org] *On Behalf Of *Adam Eskreis
> *Sent:* Friday, November 05, 2010 11:54 AM
> *To:* mapserver-users at lists.osgeo.org
> *Subject:* [mapserver-users] Tiger line file and mapserver
>
>
>
> Hello everyone.
>
> I'm having a problem with the Tiger line file in mapserver that I can't
> seem to work out.  I am using mapserver as my backend and openlayers as my
> frontend.  I'm not sure if my configuration is off, but I put on the layer
> in openlayers, and the angle of the lines seems to be a bit off.  If you
> look at, for instance, openstreetmaps.org (who also uses the tiger file)
> in the area of new york city, all the blocks are perfect rectangles.
> However, in my map, these same boxes seem to represent more of a shape
> similar to a parallelogram with acute and obtuse angles at the corners.
>
> I inspected the code of openstreetmaps.org, and looked at their openlayers
> code.  They have something similar to this for their map declaration:
>
> map = new OpenLayers.Map('map', {
>       controls: [
>          new OpenLayers.Control.PanZoomBar()
>       ],
>       units: "m",
>       maxResolution: "156543.0339",
>       numZoomLevels: 20,
>       displayProjection: new OpenLayers.Projection("EPSG:4326")
>    });
>
> I tried using this on my map (which also uses the tiger file), but I cannot
> get it to scale properly.  On the most zoomed in level, new york city is
> just a tiny dot, and if I zoom out I can't see anything.  Here is my mapfile
> code:
>
> MAP
>   NAME "basemap"
>   STATUS on
>   SIZE 800 600
>   EXTENT -180 -90 180 90
>   IMAGECOLOR 250 250 250
>   IMAGETYPE 'AGGA'
>   CONFIG "MS_ERRORFILE" "/var/tmp/ms.log"
>   DEBUG 5
>   WEB
>     METADATA
>       "wms_srs" "EPSG:4326"
>       "wms_onlineresource" "
> http://mydomain.com/cgi-bin/mapserv?map=/var/www/htdocs/dev/modules/maps/basemap.map
> "
>     END
>   END
>   PROJECTION
>     "init=epsg:4326"
>   END
>
>   FONTSET "fonts.txt"
>
>   OUTPUTFORMAT
>     NAME "AGGA"
>     MIMETYPE "image/png"
>     DRIVER "AGG/PNG"
>     IMAGEMODE "RGBA"
>     TRANSPARENT TRUE
>     EXTENSION "PNG"
>     FORMATOPTION "INTERLACE=FALSE"
>   END
>  LAYER
>    name lines
>    GROUP basemap
>    TYPE LINE
>    PROJECTION
>     "init=epsg:4326"
>    END
>    STATUS on
>    CONNECTIONTYPE postgis
>    CONNECTION "[removed]"
>    DATA "the_geom from tiger_lines"
>    CLASS
>      style
>       color 131 139 131
>       width 24
>       antialias true
>      end
>      style
>       color 200 200 200
>       width 22
>       antialias true
>      end
>    END
>  END
> END
>
> Does anyone see anything that might be the reason why I cannot get my map
> to scale properly using the same exact file and openlayers code as
> openstreetmap.org?
>
> Thanks,
>
> -Adam
>
>
>
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