[GRASS-user] Newbie... Locations, Projections, Regions, choices? (long)

[Achim Kisseler]

Hi Randy,

 > I need to create 6 regional maps of the continental U.S., north and
 > south by west, central, and east. My first thought was to create 7
 > locations (one for the entire continental US) but my second thought was
 > to create just one location with the default region as the entire
 > continental US and 6 other regions. Is this sound logic?

Just a personal suggestion:
Here I suggest to create one location with 6 mapsets if you have huge 
vector maps. You can store the basic data in PERMANENT. Otherwise just 
create one mapset, make your map and zoom to the areas of interest. Here 
you can store combination of layers and how they are displayed as 
"workspaces".

 >
 > The map displays fine but I want to change the projection to Albers
 > Equal Area or Lambert Conformal Conical since it is such a large area.
 > So I created a new location: aeaConUS with one caveat. It said the
 > eastern value had to be larger than the western value so I (perhaps
 > wrongly) used –125 for the western boundary and –67 for the eastern.

done well

 >
 > When I first try to display this map, nothing is displayed unless I
 > select “Zoom display to selected map” at which point my nice Albers map

This is a problem I have, too.

 > gets displayed. Or I can “zoom out” about 20 times to make the Albers
 > map start showing up near the top of the screen. Obviously I’m doing
 > something wrong here but I’m not sure if its the units (meters vs miles)
 > or something more fundamental.
 >

I don't know why this happens. Its not the meters-miles thing. Exporting 
and importing helps, but that's not a real solution.



Achim