[GRASS-dev] Starting a new location

[Helena Mitasova]

I planned to email this after the release, but given the needed  
modifications
in the startup panel text I am wondering whether the following change
would be useful to make (see the reasoning behind it below).
Change the order of options for defining new location and
modify the text to make it easier to understand
(comments, modifications are welcome, e.g. should we use
coordinate system rather than projection?):

1. Use georeferenced file
2. Select a pre-defined projection (EPSG code)
3. Define parameters of your projection

Helena

--- discussion on how to improve starting GRASS with new location-------
I looks like this may not be as difficult as percieved if we take  
into account
what the user has before he starts to work with GRASS:

User who wants to start grass may have:
1. georeferenced file with prj info
2. georeferenced file but no prj - should we try to guess the coord.  
system -
lat/long would be easy, UTM maybe?, state plane would be a lot of  
work, I don't know
about the rest of the world.  I don't think that you can guess a datum?
3. non-georeferenced file
4. nothing - can this happen?

I think that most users will have 1. or 2. (when using official sources
it should really be 1.)

So we can first re-arrange the startup menu to encourage people use 1.
and then make it easier to set it up for case 2:

1. put "Use georeferenced file" option first
this option should take care of both the coordinate system and region  
(spatial extent)

2. "Use EPSG values" would stay second choice but we can make it
more user friendly:
- please suggest a more intuitive text: for example,
"Select a pre-defined projection (EPSG codes)"
- is it possible to make EPSG list searchable? for example by the state,
name of the projection, datum (I knew what I wanted but it took me  
forever to find
it in the list)
This option does not create default region, so that is one piece of
the interface  that needs to be created. A really nice thing would be  
a little world
map where you could zoom in to your approximate area and the  
resolution would
be set automatically so that the no. of rows or cols does not exceed  
e.g., 1000.
(projecting lat/long into the given projection may be needed, so this  
may be more
complex than I thought)
The option to type or paste in the coordinates should be there too.

3. "Use projection values" should be last (most difficult) option
(your coordinate system is not in EPSG and your georef file does not  
have the adequate
projection/datum information or you don't have any georef. file)
- should we change the text to something more intuitive, e.g.,
"Define parameters of your projection"?
- should we have a separate button for starting with non- 
georeferenced (x,y) location
which is easy to set up?
the rest is pretty complicated and may need a separate discussion.