Re: [R-sig-Geo] question about variogramST

2013-02-24 Thread Piero Campalani
(a side note: not italian, but *spanish* ;) ) Piero On 24 February 2013 20:51, Edzer Pebesma edzer.pebe...@uni-muenster.dewrote: Erin, see https://stat.ethz.ch/**pipermail/r-sig-geo/2013-**February/017577.htmlhttps://stat.ethz.ch/pipermail/r-sig-geo/2013-February/017577.html (where the

Re: [R-sig-Geo] missing vgmST?

2013-02-19 Thread Piero Campalani
Hi Erin, ...did you load the library? Piero On 20 February 2013 01:30, Hodgess, Erin hodge...@uhd.edu wrote: Hi! I'm working with some spatio-temporal data and was trying to use vgmST. However, it says that the function is not there. I have the spacetime library running. Any

Re: [R-sig-Geo] Cross-validation with spacetime

2013-01-22 Thread Piero Campalani
01:53 PM, Piero Campalani wrote: Dear list, I was wondering if there is a way to automatically compute x-validation with the new spacetime objects (as is in gstat::gstat.cv). Looking through the available functions it does not look so, thus I bet I just need to manually run it. ? I

Re: [R-sig-Geo] Weird experimental 3D spatiotemporal variogram

2013-01-15 Thread Piero Campalani
, unless you have duplicate measurements. On 01/10/2013 03:20 PM, Piero Campalani wrote: Dear list, I am predicting PM measurements on a spatiotemporal grid with monthly intervals in time. At modeling time, I am looking at the experimental 3D variograms (`wireframes`) but I see that weird

[R-sig-Geo] Cross-validation with spacetime

2013-01-13 Thread Piero Campalani
Dear list, I was wondering if there is a way to automatically compute x-validation with the new spacetime objects (as is in gstat::gstat.cv). Looking through the available functions it does not look so, thus I bet I just need to manually run it. ? Thanks, Piero [[alternative HTML

[R-sig-Geo] Block spatiotemporal kriging with separable covariance model

2013-01-13 Thread Piero Campalani
Dear list, is there a way to have block-kriging predictions when using spatio-temporal with separable covariance model, in particular by using the gstat/spacetime suite. ? I saw examples of block kriging when using a 3D metric kriging, with rescaled time axis, so that a parallelepiped can be set

Re: [R-sig-Geo] Block spatiotemporal kriging with separable covariance model

2013-01-13 Thread Piero Campalani
Dear Edzer, thanks for the help. Is block-kriging possible with this kind of covariance model, or is it just not implemented in the `spacetime` package? On 13 January 2013 18:31, Edzer Pebesma edzer.pebe...@uni-muenster.dewrote: I saw examples of block kriging when using a 3D metric kriging,

[R-sig-Geo] Weird experimental 3D spatiotemporal variogram

2013-01-10 Thread Piero Campalani
Dear list, I am predicting PM measurements on a spatiotemporal grid with monthly intervals in time. At modeling time, I am looking at the experimental 3D variograms (`wireframes`) but I see that weird decreasing behavior in time (see wireframes_2008-1.eps for January 2008): there is a peak at 0

Re: [R-sig-Geo] STFDF with n variables

2012-12-16 Thread Piero Campalani
Thank you Edzer, comments inline On 16 December 2012 19:19, Edzer Pebesma edzer.pebe...@uni-muenster.dewrote: Yes, that works: class(stMeuse) [1] STFDF attr(,package) [1] spacetime dim(stMeuse) space time variables 10 2 4 I could see that a STFDF

Re: [R-sig-Geo] How to perform a variogram model in gstat?

2012-09-25 Thread Piero Campalani
Hi Julia, initial variogram values just need to be sufficiently reasonable from where to start fitting. I know about some known rule-of-thumb: + sill: the total variance of your data; + range: half the diagonal of your bbox; + nugget: the measurement error. You can also decide whether to

[R-sig-Geo] Discontinuities in KED prediction with `nmax` set

2012-06-10 Thread Piero Campalani
Dear list, I have a set of ~130 ground stations measurements and several grid covariates with which I am spatialising the ground point values. I am using external drift kriging: I noticed discontinuities in the predicted map when using a _localized_ prediction, hence restricting the neighbors

Re: [R-sig-Geo] LatLong to UTM

2012-06-06 Thread Piero Campalani
Hi Romina, looking at { http://spatialreference.org/ref/epsg/32721/ } I can see the UTM zone 21H or also 21S for South spans longitudes in the range (-80,-60) so I guess you just inverted easting and northing in your code: So: $ LatLong - data.frame(Y=-35.14189, X=-57.39206) # -- X is the

Re: [R-sig-Geo] How to properly use rsaga.close.gaps()

2012-06-01 Thread Piero Campalani
Thanks Giuseppe, I actually can see that the Close Gaps with Spline is mentioned in the documentation, but no further info is proposed. Asking the SAGA CMD I can only get the usage (which I already knew from `rsaga.get.usage(lib=grid_tools, module=7)`: $ saga_cmd libgrid_tools.so Close Gaps

Re: [R-sig-Geo] help to change charactwer name in a row of data.frame

2011-09-21 Thread Piero Campalani
Dear Gianni, The R Help mailing list should bemore suitable for these kinds of question: http://r.789695.n4.nabble.com/R-help-f789696.html You may consider reading some R book also, e.g. R In a Nutshell: http://www.amazon.com/Nutshell-Desktop-Quick-Reference-OReilly/dp/059680170X or at least the

Re: [R-sig-Geo] Cokriging unbiasedness condition

2011-04-06 Thread Piero Campalani
Thank you. So that means that e.g. with ordinary cokriging, the one condition sum of all coefficients equal 1 is used, and not e.g. the (n+1) nonbias conditions by which the coefficients of the target variable sum to 1, whereas the coefficients of the n secondary variables sum to 0 ? I'm sorry,

Re: [R-sig-Geo] Cokriging unbiasedness condition

2011-04-06 Thread Piero Campalani
variables is 0. On 04/06/2011 01:59 PM, Piero Campalani wrote: Thank you. So that means that e.g. with ordinary cokriging, the one condition sum of all coefficients equal 1 is used, and not e.g. the (n+1) nonbias conditions by which the coefficients of the target variable sum to 1, whereas