Hi Tom, I do not know about R but you might take a look at the GSLIB codes. It has executables for both tasks using a simplfied GEOEAS format. I recently did some Normal Score Kriging and use a combination of GSLIB, GEOEAS, and R (for the contouring of the resulting grid). BTW I used GEOEAS instead of one of the R packages because of the way the distance in each lag is calculated. I have not explored the matter but my impression is some codes/packages use the mid-point of each lag interval and some use the average pair distance for the interval...need to look at that sometime [Moral: use packages with caution--not because of any inherent flaw but because of differences in approach. You need to know what is being done.]
Regards, Michael Grant --- Thomas Adams <[EMAIL PROTECTED]> wrote: > List: > > 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. > > Regards, > Tom > > > -- > Thomas E Adams > National Weather Service > Ohio River Forecast Center > 1901 South State Route 134 > Wilmington, OH 45177 > > EMAIL: [EMAIL PROTECTED] > > VOICE: 937-383-0528 > FAX: 937-383-0033 > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
