[GRASS-user] mercator

[Steve Smith]

I am trying to reproject data from a lamber conformal conic (lcc) projection to a mercator projection. The reproject appears to go well. The output is listed below. However, when I attempt to display the data I get the message: The bounding box of the map is outside the current region. So I use g.region to change the bounds of the region to: 50, 20, -40, -100, but I still get the same error message. As a test, I created another Location, this time as Global LatLon, and after reprojecting the data, from my lcc projection, I was able to display the data, after changing the bounds of the region to the values above.  I think the problem may be in how I created the mercator projection. When I run v.info on my data the projection info is:

Projection: x,y (zone 0)                      
           N: 4370846.189    S: 3988531.316                               
           E: -8414703.985    W: -9288507.105                             
           B: 0.000         T: 0.000

It does not say I have a mercator projection?  When I created the location, I selected merc as my projection, declined to select a datum (wgs84 was used by default), and then when it asked for an ellipsoid I selected sphere, with the following settings:

lat_ts=0, lon0=0, k=1, a=6378137.0, north=85.05112878, south=-85.05112978, west=-180, east=180, nsres=0.00000904, ewres=0.00000898

Steve

Below is the output from my reproject:

v.proj input=urbnarea location=NorthCarolina mapset=PERMANENT dbase=/var/www/html/mapdata/grassdata output=NCurbnarea

Input Projection Parameters: +proj=lcc +lat_0=33.7500000000 +lat_1=34.3333330000 +lat_2=36.1666600000 +lon_0=-79.0000000000 +x_0=609601.2200000000 +y_0=0.0000000000 +a=6378137 +rf=298.257222101 +no_defs +towgs84=0.000,0.000,0.000
Input Unit Factor: 1

Output Projection Parameters: +proj=merc +lat_ts=0.0000000000 +lon_0=0.0000000000 +k_0=1.0000000000 +a=6378137 +b=6378137 +no_defs
Output Unit Factor: 1

Creating vector file...
Building topology ...
Registering lines:    1000
1968 primitives registered     
Building areas:


666 areas built     
183 isles built
Attaching islands:

Attaching centroids:

Topology was built.
Number of nodes     :   1485
Number of primitives:   1968
Number of points    :   0
Number of lines     :   0
Number of boundaries:   1311
Number of centroids :   657
Number of areas     :   666
Number of isles     :   183
Number of areas without centroid :   9
       
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