[R] Normal score transform of spatial data

From: Thomas Adams <Thomas.Adams_at_noaa.gov>
Date: Sat 29 Jul 2006 - 03:58:15 EST


I have 2 related questions:

(1) first I have x-y-z data, where x & y are the geographic locations of
point values, z. I need to perform a normal score transform on the z-values and maintain their geographic location. So, how do I go from columns x-y-z to x-y-z-t (or x-y-t), where the t-values are the normal score transforms of the z-values? Can I use qnorm(ppoints(data)) to do this; how?

(2) I also need to do a reverse transform of a matrix of normal score
values (v) to my original data value units; I have seen that I can use something like approx(t, x, v)$y. Again, the matrix represents a spatial grid. So, how do I maintain the same spatial ordering resulting from the reverse transform?

Thank you for your help.


Thomas E Adams
National Weather Service
Ohio River Forecast Center
1901 South State Route 134
Wilmington, OH 45177

EMAIL:	thomas.adams@noaa.gov

VOICE:	937-383-0528
FAX:	937-383-0033

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Received on Sat Jul 29 04:01:20 2006

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