[R-sig-Geo] STFDF with n variables

2012-12-16 Thread piero campa
Dear list, I am going to build a spacetime::STFDF object where the n spatial locations hold h different values (different fields) over the m times. Along the documentation (spacetime vignette, ?stConstruct, ?STFDF, ?reshape) I only found examples with layout of {n·m·1} observations, and not

[R-sig-Geo] Time-extent/time-lag in spatiotemporal variograms

2012-12-09 Thread piero campa
Dear experts, rather than a technical question, this is more about how to set up a model for spatiotemporal kriging predictions. With special regard to the fitting of a spatio-temporal model, whichever the covariance model I want will use, I was wondering /how deep/ in time should my `spacetime`

Re: [R-sig-Geo] Making web-repository of gridded maps: NetCDF or WKT Raster?

2012-06-25 Thread piero campa
Dear Tomislav, could you eventually manage to develop some R example for WCPS queries? I am going to ingest some spatio-temporal raster collection into rasdaman, and I was interested in a direct access from inside R to this data. Thanks for any hint, Piero -- View this message in context:

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

2012-05-20 Thread piero campa
Dear list, after reading through Spatio-temporal prediction of daily temperatures using time-series of MODIS LST images (Hengl et al., http://dx.doi.org/10.1007/s00704-011-0464-2), I wanted to try out these SAGA *grid_tools* modules to fill the gaps in my MODIS AOT datasets. I tried to follow

[R-sig-Geo] Variable point size with spplot

2012-03-26 Thread piero campa
Dear list, I used to plot points of variable size with spplot this way: library(RColorBrewer) data(meuse) coordinates(meuse) - ~x+y spplot(meuse, zcol=om, col.regions=colorRampPalette(brewer.pal(7, PuBu)[-(1:1)])(20), scales=list(draw=TRUE), cex=.4*(1:5) ) but now,

[R-sig-Geo] sp::overlay problem

2011-04-12 Thread piero campa
Dear list, I have a SpatialGridDataFrame, whose SRS is EPSG:32632: +init=epsg:32632 +proj=utm +zone=32 +ellps=WGS84 +datum=WGS84 +units=m +no_defs +towgs84=0,0,0 I am willing to overlay these grid values over point locations defined in a SpatialPixelsDataFrame with a different SRS using the

Re: [R-sig-Geo] Cell Declustering

2011-03-23 Thread piero campa
A quick and dirty answer would be to work with grids, and e.g. retain a single value in each grid cell: that's what I would like to do, since my points pattern is highly clustered. I thought I could do something like: overlay(points, grid, fn=mean) but looking at methods?sp::overlay it seems

Re: [R-sig-Geo] Missing values with lm

2011-03-03 Thread piero campa
Hi, Jan also wrote: so i expect to get 36 s values and 480 t values. Instead for the first cell and the first timestep the value is missing, the lm result is only 35 s values and 479 t values ( + one intercept coefficient ). Is there a reason behind this and some way to fix it? Any clue about

Re: [R-sig-Geo] Ordinary and Regression Kriging combined to deal with missing values in predictor variables

2011-02-24 Thread piero campa
Maybe this is how the combination is meant to be: - apply regression model on the area of interest - use the residuals at sampling location of the target variable to create direct- and cross-variograms along with the non-ubiquitous predictors - apply co-kriging by means of these variograms to

Re: [R-sig-Geo] Ordinary and Regression Kriging combined to deal with missing values in predictor variables

2011-02-14 Thread piero campa
Dear list, a slightly different scenario: what if one has a set of ubiquitous predictors and e.g. one predictor which has a limited number of observations? Hengl in his book A practical guide to geostatistical mapping suggests (probably) to combine RK with CK so that additional, more densely

Re: [R-sig-Geo] R-spatial intensive PhD course 3-10 May 2011

2011-02-14 Thread piero campa
If any of the participants is interested in finding a shared accommodation, please contact me. Cheers, Piero -- View this message in context: http://r-sig-geo.2731867.n2.nabble.com/R-spatial-intensive-PhD-course-3-10-May-2011-tp5983951p6023564.html Sent from the R-sig-geo mailing list archive

Re: [R-sig-Geo] Universal Kriging with factor covariate

2011-02-10 Thread piero campa
Ok sure. I will hereby simulate the interpolation of a target variable points (whose data is attached) via a single factor predictor classes created randomly over the region of interest: # libraries library(sp) library(gstat) library(automap) # Import the point pattern from the txt file and

Re: [R-sig-Geo] Universal Kriging with factor covariate

2011-02-10 Thread piero campa
That's it. Thank you! Piero PS: To let the example work actually before calling krige() you should run this command: names(SPgrid) - CL Moreover the right krige call is the following: pm10.rk - krige(as.formula(lm$call$formula), points, SPgrid, rvar$var_model) -- View this message in context:

Re: [R-sig-Geo] how to do a principle component analysis with geo-referenced points

2011-02-07 Thread piero campa
Hi list, I'm applying a PCA to a georeferences set of variables. As in A practical Guide to geostatistical mapping by Hengl, I'm using the command prcomp in R. To recover the georeference of the principal components (which could have some NA) it is suggested to use the values available in the

Re: [R-sig-Geo] temperature interpolation -- was: 3D kriging with gstat

2011-01-26 Thread piero campa
This is more about kriging theory actually, but I can't understand in which different ways the elevation information is taken into account in the prediction process when e.g.: - I apply ordinary cokriging on input data which include 3D (x,y,h) spatial coordinates; - I apply universal cokriging

[R-sig-Geo] Global or local variogram model

2010-12-21 Thread piero campa
Hi, this is not a technical question, and maybe I shouldn't post it here. Anyway, let's say you have several georeferenced datasets of a same variable to be interpolated, each one representing different days, for example. Is it better to compute offline a unique variogram model over the WHOLE

Re: [R-sig-Geo] Continuous colorbar legend for a SpatialPointsDataFrame object

2010-12-21 Thread piero campa
I would submit the same question. Piero (Pierre, did you manage somehow then?) -- View this message in context: http://r-sig-geo.2731867.n2.nabble.com/Continuous-colorbar-legend-for-a-SpatialPointsDataFrame-object-tp4805804p5855549.html Sent from the R-sig-geo mailing list archive at