Hi,<br><br>I'm a GIS novice, trying to reproject a vector layer. My objective is to get a world map <br>projected into Lambert Equal-Area, centered on the north pole. I chose this projection <br>as it shows the entire arctic well, but I don't have to use Lambert Equal-Area <br>
specifically.<br><br>This is what I've tried so far:<br><br>Created a new location with the location wizard, selecting <br> 'read projection and datum terms from georeferenced data file'<br><br>The target file was:<br>
WorldCountries.shp<br><br>retrieved from <a href="http://www.sharegeo.ac.uk/handle/10672/124">http://www.sharegeo.ac.uk/handle/10672/124</a> <br><br>This appears to be correct, as I now have my location world-ll, which contains in the<br>
PERMANENT mapset the layer WorldCountries. The region info is:<br><br>g.region -p <br>projection: 3 (Latitude-Longitude)<br>zone: 0<br>datum: wgs84<br>
ellipsoid: wgs84<br>north: 83:37:38.7084N<br>south: 90S<br>west: 180W<br>east: 180E<br>nsres: 8:40:52.93542<br>ewres: 18<br>rows: 20<br>cols: 20<br>cells: 400<br><br>I then made a new location, using the wizard again:<br>
select coordinate system from a list: laea<br> central parallel: 90<br> central meridian: 100<br> false northing: 0<br> false easting: 0<br> datum code: wgs84<br><br>I then set the extent to 90N, -90S, 180E, -180W, NS resolution 0.1, EW resolution 0.1<br>
<br>The resulting region info is:<br><br>g.proj -p <br>-PROJ_INFO-------------------------------------------------<br>name : Lambert Azimuthal Equal Area<br>
proj : laea<br>datum : wgs84<br>ellps : wgs84<br>lat_0 : 90<br>lon_0 : 100<br>x_0 : 0<br>y_0 : 0<br>no_defs : defined<br>-PROJ_UNITS------------------------------------------------<br>
unit : meter<br>units : meters<br>meters : 1<br><br><br>From here I used the gui to import the WorldCountries vector layer from world-ll,<br>generating the command:<br><br> v.proj input=WorldCountries location=world-ll mapset=PERMANENT output=WorldCountries<br>
<br>This command runs without error, but with a few suspicious warnings:<br><br> v.proj input=WorldCountries location=world-ll mapset=PERMANENT output=WorldCountries<br> Building topology for vector map <WorldCountries>...<br>
Registering primitives...<br> 55402 primitives registered<br> 417249 vertices registered<br> Building areas...<br> Area of size = 0.0 ignored<br> Area of size = 0.0 ignored<br> 27423 areas built<br> 26809 isles built<br>
Attaching islands...<br> Attaching centroids...<br> Number of nodes: 54788<br> Number of primitives: 55402<br> Number of points: 0<br> Number of lines: 0<br> Number of boundaries: 28000<br> Number of centroids: 27402<br>
Number of areas: 27423<br> Number of isles: 26809<br> Number of incorrect boundaries: 1<br> Number of centroids outside area: 1<br> Number of areas without centroid: 22<br><br>At this point, the WorldCountries layer appears in the Map Layers tab, but not on the<br>
display. Zooming to selected layer produces an error: <br> Unable to zoom to vector map <WorldCountries@PERMANENT><br><br>What have I done wrong?<br><br>Thanks!<br><br>Tyler<br><br>