moon landing

Chris C Rewerts rewerts at
Wed Jun 10 22:03:39 EDT 1992

I just put four files on the moon's incoming directory: 


here's the scoop:

d.linegraph is a new creation. I wrote it (by modifing d.histogram, for
the most part) because I wanted a way to plot line graphs from the output
of simulation program I have linked to grass. Input, then, is files of
numbers to be graphed. one file of numbers is needed for x and up to
10 files can be used for y lines. This program is no where near as snazy
as other public domain graph and plot programs, but it does what I want
and it does it on the grass monitor. hey, its a real fixer-upper if you
please, bend it and make it do your bidding.

d.rast.edit was available in "src.alpha" with the grass 4.0 release last
summer. since then we have run it around the block a few times and I
have been under the hood a few times to fix a few of its less endearing
qualities. meanwhile, if you haven't been introduced, d.rast.edit grew
out of our need to graphically edit individual cells in raster maps. our
primary use is editing flow path maps for watersheds, hence its companions...

d.rast.arrow, gives a means to better see the computed flow direction
of an aspect map by drawing little arrows on each cell. it knows about
3 types of aspect map values: those used by grass, and those used by
the agnps and answers watershed simulation programs.  of course,
it is no fun using d.rast.arrow unless you have zoomed in for a close
look at your map, so that you can see the individual cells. ok, then
we wrote d.rast.zoom, which is kind of like the d.zoom program, but 
different. anyway, d.rast.edit uses d.rast.zoom as one of its functions,
so they are a team cluster of programs. d.rast.num is part of the
team, but I don't think there is anything that we have changed in it
since its inclusion in src.alpha, so I didn't upload it tonight.
d.rast.num is like d.rast.arrow, only more general. Instead of drawing
arrows is draws the numerical cell value on top of the displayed cell.

I think each file will uncompress and un-cpio (usage: cpio -iduc < filename)
with README's and man pages to help with more details. 

Chris Rewerts      (rewerts at
Agricultural Engineering, Purdue University        

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