moon landing

Darrell McCauley mccauley at
Thu Jun 11 09:03:13 EDT 1992

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

More information about the grass-user mailing list