moon landing

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moon landing

Chris C Rewerts

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      ([hidden email])
Agricultural Engineering, Purdue University        

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Re: moon landing

James Darrell McCauley

One more touchdown on moon...

s.medp.shar.Z - performs a median polish ("another statistical dance") on
                sites data. A vector grid (possibly rotated) is input and
                sites find their nearest node. Then, medians are removed
                from rows, then columns, then rows, etc, until
                convergence. The residuals (and optionally row, column,
                and all "effects") are stored in a vector output file.

This will most likely be replaced with v.medp.shar.Z in the near future...

I just thought that I would make this available in case the few people
who know of this algorithm would like to test it out. A man page (with
a reference) is included for those who would like to find out more about
this algorithm.  

Basically, it detrends data so that you minimize problems with
non-stationarity when attempting to use kriging.  The row, column, and
all "effects" *could* be used to create a trend surface (though this
has not been implemented).

Darrell McCauley
Agricultural Engineering
Purdue University