NAME
d.zoom - Allows the user to change the current geographic
region settings interactively, with a mouse.
(GRASS Display Program)
SYNOPSIS
d.zoom
d.zoom help
d.zoom [-q]
[rast=name[,name,...]]
[vector=name[,name,...]]
[site=name[,name,...]]
[action=name]
[zoom=value]
DESCRIPTION
d.zoom allows the user to interactively adjust the settings
of the current geographic region using a pointing device such as
a mouse.
Like g.region,
d.zoom re-defines the settings of the geographic
region. However, d.zoom allows the user to change
the current region settings interactively, by either
outlining the new region perimeter with a mouse,
"rotating" latitude-longitude data into the current region or unzoom
the region. The graphics display is updated by the module.
OPTIONS
Flag:
- -q
- Run quietly, suppressing output of some program
messages to standard output.
Parameter:
- rast=name[,name,...]
- Name of raster map(s)
- vector=name[,name,...]
- Name of vector map(s)
- site=name[,name,...]
- Name of site map(s)
- action=name
- Allows the user to change the geographic region
settings by "rotating" the globe to move a different
portion of the globe into the stationery boxed region
outline (making this new portion of the globe the new
current region), rather than by moving the boxed region
outline. This option can only be used with
latitude-longitude data bases (although d.zoom
will not complain if the user attempts to set this
parameter while running on a non-latitude-longitude data
base).
Options: zoom, rotate
- zoom=value
- magnification: >1.0 zooms in, <1.0 zooms out
options: 0.001-1000.0
default: 1.0
After the user types the command d.zoom and
(optionally) sets the -q flag and type of zoom to be
performed, a mouse-button menu will appear, directing the
user to: establish the corners of the new geographic
region, check its coordinates, and confirm any changes
made. When the user accepts new geographic boundaries,
d.zoom asks,
-
Accept new region? Y / N >
If the user clicks the mouse over the "Y" (yes),
the mouse-drawn geographic region is saved as the user's
current geographic region.
To zoom-out to a larger area than was windowed-in on with d.zoom
(i.e., to enlarge the current geographic region),
the user may use the middle mouse button. The stepsize can be adjusted
by zoom parameter. Additionally the region settings can be modified by
running g.region.
The user may also alter the current geographic region by running the "region"
option of the d.display program.
NOTES
Although it is not necessary that the user display a map in
the active display frame before running d.zoom, it
is helpful to do this for reference.
SEE ALSO
d.display
d.erase
d.pan
d.rast
d.sites
d.vect
g.region
AUTHOR
Michael Shapiro,
U.S. Army Construction Engineering
Research Laboratory
Improvements by Huidae Cho and Markus Neteler