similar to: Connectivity across a grid above a variable surface

I have been using the sp package to deal with gridded data. I would like to know how to extract the vertices (x,y) of polygons that outline areas of like-valued cells in a grid. Here is a simple 3x3 grid: 2 2 1 1 2 1 1 1 3 x <- c(1,1,1,2,2,2,3,3,3) # define a 3 x 3 array of points y <- c(1,2,3,1,2,3,1,2,3) h <- SpatialPoints(cbind(x,y)) # make these an sp object of the points

I wanted a simple function for bilinear interpolation on a 2-D grid, and interp.surface() in the fields package didn't quite suit my needs. In particular, it requires uniform spacing between grid points. It also didn't have the "visual" reference frame I was looking for. Here is an alternative function, followed by an example. # A function for bilinear interpolation on a 2-d

When I generate levelplot figures with Postscript, the lines from the underlying grid (i.e., the x and y in z ~ x* y) show up as faint white lines in the output. If I have a dense grid, the lines wash out the contour colors. I can avoid the problem if I use png instead, but that brings up other problems. Any ideas for how I can get Postscript to not show those lines around the cells? Scott

John Rosatti, Excavators, 3D, NASA and Why Should I care? Well, because! There are two definitions for excavator; one is any person engaging in excavation is called an excavator. The second definition of excavator is, of course, the vehicles called excavators, which are sometimes called diggers, trackhoes, fronthoes, and 360-degree excavators or just 360. This is not to be confused with

*Dear **Madam**/**Sir,* *What would happen if we irrigate the degraded land using the desalinated saline water in Minqin Oasis, Gansu Province, China? Can we prevent the disappearing of Minqin Qasis?* * * *Background:* *1. **The Minqin Oasis is surrounded by two deserts, Badain Jaran Desert and Tengger Desert. * *2. **Water is the root of ecological

Dear R users, It is a pleasure for me to announce the availability of the new package kwb.hantush (0.2.1)? on CRAN. Its objective is the calculation of groundwater mounding beneath an (stormwater) infiltration basin by solving the Hantush (1967) equation. For checking the correct implementation of the algorithm the R modelling results were cross-checked against alternative models assessed in

Dear R users, It is a pleasure for me to announce the availability of the new package kwb.hantush (0.2.1)? on CRAN. Its objective is the calculation of groundwater mounding beneath an (stormwater) infiltration basin by solving the Hantush (1967) equation. For checking the correct implementation of the algorithm the R modelling results were cross-checked against alternative models assessed in

I am trying to fit a nonlinear regression to infiltration data in order to determine saturated hydraulic conductivity and matric pressure. The original equation can be found in Bagarello et al. 2004 SSSAJ (green-ampt equation for falling head including gravity). I am also VERY new to R and to nonlinear regressions. I have searched the posts, but am still unable to determine why my data come up

I am using levelplot() from lattice with grids that have unequal cell sizes. This means that the boundary between two cells is not always half-way between nodes, as levelplot() assumes. The result is that some cell sizes are rendered incorrectly, which can be painfully obvious if using relatively large cells. Is there any work-around? I am using the conditioning capability of lattice and

Hi all, I'm trying to make multiple lattice contour plots which have the same color key, to allow good comparisons. However, I run into some problems when fitting the plots to the color key. Basically my strategy to tackle this problem was: 1) define a color key for all plots; 2) calculate the variable range for each plot; 3) calculate the range of colors from the color key that correspond

R-2.2.1 is still not available for Redhat Linux as an RPM on CRAN. It is available as an SRPM. Can someone fill me in on why it takes so long to make RPMs available? I would be happy to help make the RPMs for el4 and el3 if such help is needed. Regards, Scott Waichler Pacific Northwest National Laboratory scott.waichler _at_ pnl.gov

How can I get the value of the aspect ratio that is used in a lattice plot? In a levelplot for instance, the native units per cm of my x and y axes are different, and I need to know the aspect ratio so that I can correctly plot vectors. I know how to set the aspect in a high-level lattice function but I can't quite figure out how to get it. I would like call to levelplot() without printing

I use some computers that run older versions of Redhat Linux such as EL3. RPMs for the current version of R are no longer provided via CRAN for these older operating system versions. How can I compile my own RPM for the current version of R, which I could then use to install R quickly and easily on multiple machines? Perhaps the answer to this would be a useful addition to the manual R

Hi, I often use the mod() and instring() functions that are available in the clim.pact package. This package has a lot of dependencies, including installation of netCDF, and I haven't yet been able to get library(clim.pact) to work on a Mac OS 10.4.6. A previous request for help with the Mac problem yielded no results, so now I wonder if I could just extract the definitions for the couple

Hi, I am trying to install packages in R-2.2.1 on a Redhat WS4 system. I get the following error messages trying to install, for example, the akima package: > R.version.string [1] "R version 2.2.1, 2005-12-20" > install.packages("akima", lib="/usr/lib/R/library", repos = "http://cran.fhcrc.org/") . . . gcc -shared -L/usr/local/lib -o akima.so

Hello, I would like to fill the rows of a Latex tabular environment with output from R, as in \begin{table} \caption{Table caption.} \label{tab:events} \begin{tabular}{c r r r r r} \hline <<echo=false,results=tex>>= fill.my.table.rows() @ \end{tabular} \end{table} Sweave produces the output inside \begin{Schunk} and \end{Schunk} commands, which latex doesn't

Hi, I'm trying to install rimage on a Mac OS X 10.4 machine. I followed the advice in previous R-help threads and got over the hurdles of having the header files in the right places, among other things. But I can't figure out what to do with this error. ice.pnl.gov:/home/waichler<949>system_profiler -detailLevel mini SPSoftwareDataType Software: System Software Overview:

Hello, I am trying to do model autocalibration using the snow and rgenoud packages. The function I want to run in task-parallel fashion across multiple machines is one that pre- and post-processes data and runs an external model code. My problem is that external file I/O is happening only in the master node and not in the slaves. I have followed Jasjeet Sekhon's suggestion to test the

Karline, Thank you for your help. I discovered that in addition to including clim, I needed to omit breaks. This code uses one of your other examples as a starting point and works as intended: persp3D(z = volcano, zlim = c(-60, 200), phi = 20, colkey = list(length = 0.2, width = 0.4, shift = 0.15, cex.axis = 0.8, cex.clab = 0.85), lighting = TRUE, lphi = 90, clab =

OBJECTIVE: Richard's Resume for Job, Consulting or Service Sr. MECHANICAL & DESIGN ENGINEER Project Mgr, Electro-Mechanical Design, Mfg, Product Development, R&D, CADD Tel: ( 408) 309-7006 rpraca9 at yahoo.com EXPERIENCE: 08/93-present Sr. MECHANICAL & DESIGN ENGINEER, CADD Mgr "Mech-Tronic" Engineering, Design