[GRASS-user] Long post - Remote Sensing - Classifications

[Hamish]

Hamish:
> > this gets i.class working for me using the sample Spearfish imagery
> > dataset:
> > 
> > g.region rast=spot.comp
> > d.mon x0

mitch:
> When I do that, I get the following warning using the wxPython GUI.
> http://n2.nabble.com/file/n2389455/dx0.png

run that from the terminal prompt, not from the wx GUI.



> > I'm not sure what good results are supposed to look like.
> 
> That's the point. Isn't supposed to be a monitor display?

i.class should bring up an interactive workspace in the Xmon with control
buttons in along the bottom etc.

screenshot here:
  http://bambi.otago.ac.nz/hamish/grass/screenshots/i.class_in_action.png

resulting sig file (in $MAPSET/group/$GRP_NAME/subgroup/$SGRP_NAME/sig/

#
#trial
496


when I exit the program it just says:
....
RESULT SIGNATURE
GRASS>


not sure if there should be more there. (prob have to read the imagery
tutorial)



> > > is there any way in GRASS to link different map displays
> >
> > I am not sure what you mean by that. zoom in one moves both?
> 
> 
> Yes...

not that I know of (in the wx gui; search archives for d.frame and d.mon 'd.zoom -p' + d.redraw automation attempts)

in the wx gui you could update with set/set from computation region &
redraw but it is a number of mouse clicks.


> > > and have a "brushing" (update while dragging)
> They are general simple windows displaying info regarding coordinates
> and Digital Number values like:
> 
> Diplay: #
> R:# G:# B:#
> Proj: UTM ZONE
> Map: #, # meters
> Lat Long: DD, DD

ah, try the pull-down menu on the bottom of the wx map display window

or d.text for screenshots.



> The meaning of this is allowing a visual inspection (in
> terms of either different color composition or shades of gray)
> of the same area, supported by a numerical info (DN -- therefore
> a precise representation of the reflectance behavior of different
> surfaces).

in the xmons you can 'd.rast -o' overlay the band rasters and then
d.what.rast gives you the values of all at that point.


> > or even a static d.what.rast?
> > 
> > I am not sure what you mean by that.
> > maybe r.what does what you want?
>
>
> In order to use r.what you are supposed to use a separate
> file containing the points you are querying, right?

or just type them in

> No, this is not exactly what I'm talking about...or better, the outcome
> is but it's not the interaction that I'm looking for.


> I'm talking about a pointer based like d.what.rast one.

.... but from the wx GUI


Hamish