[R-sig-Geo] resampling grids

Hi all, I apologize in advance, I haven't the time today to comb the help list for tips and hints, but does anyone know how to resample a 20 by 20m grid so the operational spacing is down to a 10 by 10m grid? Any assistance is MUCH appreciated! -- David Depew PhD Candidate Department of Biolog

[R-sig-Geo] gstat memory size

Just a quick question re: memory sizes. Is it possible to quickly estimate the amount of RAM needed to do ordinary kriging given a dataset of 14000 records for 2 variables? -- David Depew PhD Candidate Department of Biology University of Waterloo 200 University Ave W. Waterloo, ON. Canada N2L 3

Re: [R-sig-Geo] [Gstat-info] LOCAL universal kriging with GLOBAL reg. coeff.estimation

A late follow up question to this thread What if the local neighbor hood was restricted to the range of autocorrelation? My impression was that values beyond that have little weight in the interpolation anyways. I realize that this is of course not statistically optimal, but for those with

Re: [R-sig-Geo] cokriging question

rever. The other issue in that question was, I suspect, lack of standardization of coordinates, used in a trend surface. -- Edzer Dave Depew wrote: Is there a limit to the # of observations or size of file that can be co-kriged in gstat? I have a ~12000 observation data set (2 variables), the variogram

[R-sig-Geo] cokriging question

Is there a limit to the # of observations or size of file that can be co-kriged in gstat? I have a ~12000 observation data set (2 variables), the variograms, cross variogram and lmc are fit well, and co-kriging starts ok Linear Model of Coregionalization found. Good. [using ordinary cokriging]

[R-sig-Geo] nested variograms?

A quick question for experienced gstat users Can nested variograms be fit using gstat? if so, is it simply adding to an existing variogram structure? Thanks -- David Depew PhD Candidate Department of Biology University of Waterloo 200 University Ave W. Waterloo, ON. Canada N2L 3G1 (T) 1-

Re: [R-sig-Geo] kriging question

tion of the kriging model - this seems to give reasonable estimates for mean error, mean squared prediction error and mean square normalized error. I had interpreted this that the variogram model chosen was doing a reasonable job. Edzer Pebesma wrote: Hi Dave, Dave Depew wrote: Hi all, A q

[R-sig-Geo] kriging question

Hi all, A question for the more experienced geostats users I have a data set containing 2-3 variables relating to submerged plant characteristics inferred from acoustic survey. The distribution of the % cover variable is bounded (0-100) and highly left skewed (many 0's). The transect spacin

Re: [R-sig-Geo] gstat error

I suppose it might be, although I expanded the neighborhood just to be sure. I wonder if it isn;t the NA values that are in the grid Edzer Pebesma wrote: Is it possible that you're using kriging in a local neighbourhood where the predictor is constant? -- Edzer Dave Depew wrote: H

[R-sig-Geo] gstat error...resolved?

> I think I know what the issue isI have some NA cells in the prediction grid. trying to do UK with NA cells may be the problem. IS there a way to exclude these or remove them? I think they are present due to transect spacing and the short range of the original OK done for the covariate...

[R-sig-Geo] gstat error

Hi I'm trying to run some universal kriging, and have not experienced this error before. I've removed duplicate data locations using the remove.duplicates command. The data set runs fine if the formula is set as ordinary kriging, but adding in a predictor (which is already known at each grid l

Re: [R-sig-Geo] kriging

ariables. EUR 22904 EN Scientific and Technical Research series, Office for Official Publications of the European Communities, Luxemburg, 143 pp. http://bookshop.europa.eu/uri?target=EUB:NOTICE:LBNA22904:EN:HTML -Original Message- From: [EMAIL PROTECTED] on behalf of Dave Depew Sent: Mon 6/16/20

[R-sig-Geo] another kriging question

Hi again, I'm getting more confused regarding the "accepted" forms of detrending data prior to kriging. I've used a GAM (package mgcv) to detrend my target variable. The residuals from this 9th order polynomial are well behaved (normal distribution, only mild heteroskedasticity). I realize tha

Re: [R-sig-Geo] kriging

://spatial-analyst.net -Original Message----- From: Dave Depew [mailto:[EMAIL PROTECTED] Sent: dinsdag 17 juni 2008 14:57 To: [EMAIL PROTECTED] Cc: r-sig-geo@stat.math.ethz.ch Subject: re:kriging Thanks Tom, I've been able to fit a polynomial function to the data quite well. The

Re: [R-sig-Geo] kriging

Thanks Tom, I've been able to fit a polynomial function to the data quite well. The residuals are behaving (i.e normal distribution and no skewness of variance). I'm assuming this means that I could krige the residuals (Ordinary K?) and then add the trend back to the predicted residual grid? I

Re: [R-sig-Geo] kriging

the scope of universal kriging. On Mon, 16 Jun 2008, Dave Depew wrote: Hi all, I have a data set that I would like to krige to interpolate between transects. There is a non-linear trend between two of the variables...my impression from reading the gstat help file is that there must be a linear

[R-sig-Geo] kriging

Hi all, I have a data set that I would like to krige to interpolate between transects. There is a non-linear trend between two of the variables...my impression from reading the gstat help file is that there must be a linear relationship between the data to use universal kriging? Second, would a

Re: [R-sig-Geo] anisotropy gstat

Thanks Edzer, SO to confirm, the 45 deg direction is the maximum range of correlation, or simply just the maximum range to determine the angle of anisotropy? Edzer Pebesma wrote: Dave Depew wrote: Hi All, I suppose this is a rather simple question...however, I'm managing to get

[R-sig-Geo] anisotropy

Hi All, I suppose this is a rather simple question...however, I'm managing to get more confused the more I read. I'm doing some OK and UK using the R-gstat package...I have some data that is moderately anisotropic. Reading the gstat literature, it would seem that to specify the appropriate para

Re: [R-sig-Geo] kriging output

"]]<0.5) {meuse.grid[["class"]]=10*meuse.grid[["dist]]} else {meuse.grid[["class"]]=100* meuse.grid[["dist"]]} } Edzer Pebesma wrote: Dave Depew wrote: Hi all, I've got a question regarding kriging outputs. I have an interpolated dataset which due to t

[R-sig-Geo] kriging output

Hi all, I've got a question regarding kriging outputs. I have an interpolated dataset which due to the nugget effect contains some negative values as the predictions. I would like to truncate these @ "0", rather than having them as a negative prediction. I've tried something similar with the m