NAME
d.profile - Displays profiles of a user-specified raster map layer.
(GRASS Display Program)
SYNOPSIS
d.profile
d.profile map=name [plotfile=name]
DESCRIPTION
This command works only interactively. It clears the entire
graphics screen and provides a graphical interaction
allowing the selection of transects for which profiles are
then generated. Input parameters can be specified on the command line
for quicker start-up.
USER PROMPTS
First, you will be presented with a prompt asking you to
choose a raster map layer to be profiled. Next, you will
be prompted for the name out an output file for your profiles.
This is an optional feature.
Once you specify
a valid raster map layer name, the map layer will be
displayed in the left half of the graphics display, and the
right half of the dispay will be divided into four display
frames. There will also be two frames along the top of the
display: a mouse-button menu frame on the left, and a
status frame on the right.
The mouse-button menu initially offers you three options:
-
Mouse Buttons:
Left: Where am I?
Middle: Mark FIRST Point of Profile Line.
Right: QUIT this.
You may query the displayed raster map layer by indicating
points with the left mouse-button. The coordinates and
category value of each point that you indicate will be
displayed on in the status frame. If you mark the first
point of the profile line you will be presented with the
following mouse-button menu:
-
Mouse Buttons:
Left: Where am I?
Middle: Mark SECOND Point of Profile Line.
Right: QUIT this.
Once you mark the second point of the profile line, the
profile line will be labeled (with a letter from A to D)
and displayed in one of the four display frames on the
right hand side of the screen. You will then be presented
with a third mouse-button menu:
-
Mouse Buttons:
Left: DO ANOTHER
Middle: CLEAR DISPLAY
Right: QUIT this.
If you would like to view another profile, click on the
left mouse-button. If you would like to redisplay the
raster map layer and clear out the four profile frames,
click on the middle mouse-button. If you would like to
quit, then click on the right button.
If you selected the plotfile option, you will have up to
four files starting with the name and followed by a suffix
of the plot letter A, B, C, or D. The plots that
are written to these files reflect the last of each plot done with that
letter (i.e. They will match what's in the display when you quit).
The format of the plot files is not geared toward any particular software,
but should be easy to coax into a number of other programs. The first
three lines contain some header information about the plot, each prefixed
with a # sign to denote a comment. This is followed by a blank
line, and then each value for every stop along the way of the profile.
The number of values will vary depending on the length of the profile, cell
resolution and the slope angle of the profile line. Below is an example
of a plotfile:
# Profile A of fract@PERMANENT
# From (-311.5727003, 700.29673591) to (560.83086053, 267.06231454)
# Stats: Count = 45, Min = -3332.379353, Max = 1389.142386
-273.619575
-434.155326
-805.505372
...
NOTES
Useful enhancements to d.profile would include:
- Adding an option to display profiles using category
colors, like a bar-chart.
- Allowing profile lines to be defined by a series of
points, not just two.
- Allowing profiles to be saved in a file, for later
viewing by GRASS.
- Allowing the user to enter profile line points by
typing coordinates.
BUGS
None known.
AUTHOR
Dave Johnson
DBA Systems, Inc.
10560 Arrowhead Drive
Fairfax, Virginia 22030
Modified by Eric G. Miller for profile output, and support of
floating point rasters (11-Nov-2000).