[GRASS-user] Gathering all layers, defining subset -- UPDATE

[Rich Shepard]

On Mon, 21 Dec 2009, Rich Shepard wrote:

>  3) Finding the stream of interest by it's name in the vector attribute
> file and the watershed it drains (using the HUC boundaries layer), define
> the location's new boundaries to focus on that portion of the full data
> sets. Clip/mask all layers to that size.

   I've been spinning my wheels on this today and failing to make progress
despite reading man pages and trying things. Here's what I've done.

   In the source location, /usr4/grassbase/lotic, I display the stream of
interest:

   d.mon x0
   d.vect map=streams_rivers type=line where="WC_GNIS_NR=1116751" color=blue

The above displays the main stream without tributaries. Since it's quite
small I zoom in on the drainage basin:

   d.zoom

until I get all first-order streams in this coverage included, with a buffer
into the adjacent drainage basins. Next, I find the new region of this
zoomed map:

   g.region -p

which shows me the LCC values for north, south, east, and west.

   Now I try to extract them into a new map:

   v.extract input=streams_rivers output=abernethy type=line

and use the left-button to draw a box around the entire display. Eventually,
the right button allows me to exit the function which has supposedly saved
the features within the defined box.

   When I try to display this new map (a sub-set of the original, state-wide
coverage), I'm told the bounds are beyond the current region so nothing is
displayed:

GRASS 6.4.0svn (lotic):/usr4/grassbase > d.vect map=abernethy
The bounding box of the map is outside the current region, nothing drawn.

   I don't understand this at all. What have I done incorrectly that I get
this error and cannot display the supposedly extracted sub-region from the
statewide coverage?

Rich