Displaying 20 results from an estimated 1100 matches similar to: "How to generate a random field with truncated marginal distributions?"
2010 Mar 14
3
the error in DoSimulateRF function
Hello,
I am a graduate student of University of Florida.
I am trying to run a process variation model and I am facing the following
error.
-------------------------------------------------------------
Analysis of geostatistical data
For an Introduction to geoR go to http://www.leg.ufpr.br/geoR
geoR version 1.6-27 (built on 2009-10-15) is now loaded
2004 Dec 28
1
RandomFields: Controling seed with GaussRF
Hi,
I'm using RF to simulate a correlated variable with GaussRF
set.seed=1
GaussRF(sim.kfinegrid, grid=F, model="exponential",
param=c(0,0.5,0,0.2))
However when I simulate again using the same random seed I get different
results.
> set.seed=1
> summary(GaussRF(sim.kfinegrid, grid=F, model="exponential",
param=c(0,0.5,0,0.2)))
Min. 1st Qu. Median Mean 3rd
2010 Jul 28
2
Beginner stucked with raster + geoR package.
Hello everyone.
I am trying to build up understanding in R by trying to develop just some simple
scenarios.
I would like to explain you what I am trying to do and what I did so far.
I would like to put inside a RasterLayer (raster package) a Gaussian field (for
given covariance) using grf function (geoR package)
1. First I created a Raster Layer object
r <- raster() # Default values are
2007 May 21
1
size limit in R?
Hi,
Please see the email exchanges below. I am having trouble generating output that is large enough
for our needs, specifically when using the GaussRF function. However, when I wrote Dr. Schlather
(the author of the GaussRF function), he indicated that there is also a limit imposed by R itself.
Is this something that we can overcome?
Thank you very much for any assistance you may provde.
2004 May 11
1
bad interaction between RandomFields 1.1.11 and Sweave
Not really a bug (I eventually discovered), but ...
When running GaussRF()/DoSimulateRF() with n>1, the default pch="!"
prints backspaces to the terminal, which causes problems (LaTeX barfs) if
you're running this within an Sweave() job. Setting RFparameters(pch="")
fixes the problem.
Could put this in the documentation, but I don't know where you could
2008 May 08
2
anova p value extraction
hello all,
Quick question, how do I get the p value out of the anova?
Thanks,
Paul
> pb<-aov(as.numeric(diff[5,16:33]) ~ grF)
> summary(pb)
Df Sum Sq Mean Sq F value Pr(>F)
grF 3 2.7860e+10 9.2867e+09 4.2236 0.02534 *
Residuals 14 3.0783e+10 2.1988e+09
---
Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 '
2010 Sep 01
1
Looks like a bug in subsetting of a complicated object
I don't understand what is happening! I have a (large) object sim1, an
matrix list
with dim c(101,101) where each element is an 3*3 matrix. I am
subsetting that with
a matrix coo, of dim c(100,2), of unique indices, but the resulting object
has length 99, not 100 as expected.
Code reproducing the problem follows:
library(RandomFields)
set.seed(123)
sim0 <- GaussRF(x=seq(0, 100, by=1),
2011 Apr 11
1
Comparing execution times
Dear all,
In my 'simple' computer I was running some experiments to help me understand how faster a multicore lapply will be. I thought it might be interesting for some people to look at the results.
Even though are not accurate, still might be a good indicator how much improvement there can be.
A.Case. The classic: for 1:100
for (i in c(1:dimz)){
print(sprintf('Creating the %d
1999 Jun 27
2
paste and path ?
Dear friends. I have trobpe with path.
Below I have tried to paste a path and file name but it will not work
> path <- "D:/rw0641/own/own/procedures/GFR_TIME"
> path
[1] "D:/rw0641/own/own/procedures/GFR_TIME"
> path1 <- paste(path,"gfr.txt",sep="/")
> path1
[1] "D:/rw0641/own/own/procedures/GFR_TIME/gfr.txt"
-- this is good
2011 Apr 09
1
For->lapply->parallel apply
Dear all,
I would like to ask your help understand the subsequent steps for making my program faster.
The following code:
Gauslist<-array(data=NA,dim=c(dimx,dimy,dimz))
for (i in c(1:dimz)){
print(sprintf('Creating the %d map',i));
Gauslist[,,i]<-f <- GaussRF(x=x, y=y, model=model, grid=TRUE,param=c(mean,variance,nugget,scale,Whit.alpha))
}
creates 100 GaussMaps (each
2012 Feb 10
0
range and anisotropy with RandomFields
Hello,
I am presently trying to get a feel for the various packages out there that
allow me to both analyze and simulate random fields. The package
RandomFields is nice, but there are still a few aspects of its
implementation that are confusing to me and I was hoping someone could help
clarify things for me. It could also be that my questions reflect a lack of
knowledge pertaining to random
2009 Mar 10
6
Pseudo-random numbers between two numbers
I would like to generate pseudo-random numbers between two numbers using
R, up to a given distribution,
for instance, rnorm.
That is something like rnorm(HowMany,Min,Max,mean,sd) over
rnorm(HowMany,mean,sd).
I am wondering if
dnorm(runif(HowMany, Min, Max), mean, sd)
is good. Any idea? Thanks.
-james
2005 May 19
0
Random/systematic selection of rows in a matrix
Hi R people:
I am new to R. I am writing a function to (1) produce a sparse
stochastic Gaussian 2D field and (2) perform a systematic
transect sampling on this field, this carried out many times
in a simulation framework. My function does a good job at
producing the random field (a matrix of zeros and some
manifestations of the stochastic process, depending on a
parameter of the function
2010 Aug 19
0
2d kriging with anisotropy on an irregular network (RandomFields Package)
Dear List
I am using the RandomFields package, and I have a problem when 2d-kriging, with an anisotropy, some values from an irregular network.
It works well when :
- 2d-kriging, without any anisotropy, some data from an irregular network
- 2d-kriging, with and without anisotropy, some data from a regular network
- 3d-kriging, with and without anisotropy, some data from a regular network
Here is
2010 Mar 29
1
Error "grid must have equal distances in each direction"
Hello all,
I am trying to create a grid of large number of points 4096*4096, on
processing the data I am writing it into a file.
phi <- 0.5
N <- 4096
mu <- 90
sim<-grf(N*N,grid="reg",cov.model="spherical",cov.pars=c(1,phi),method="RF")
sim$data <- (sim$data - mean(sim$data)) / sd(sim$data)
local <- array(sim$data, dim=c(N,N))
sysvar <- local *
2011 Apr 11
1
Mclapply and print statement
Dear all.
I am using the mclapply function to split my code to the many cores my system has. It seems that is working fine. This is the parallel version of lcapply.
The only problem that I seem to have is that the printf cannot print messages.
The ideal to me is to have fro my function an output of the form
Shadowlist<-mclapply(1:dimz, function(i) {
print(sprintf('Creating the
2004 Oct 05
1
Bug in optim - way to solve problem?
Hi,
I want to automatically fit variograms to a large number of different
sample data sets, and call the funtion "likfit" (in package geoR) from
within a for-loop. "likfit" does again call "optim". After ssuccessfully
fitting variograms to some of the data sets, the procedure crashes and I
get the error message:
Error in optim(par = ini, fn = negloglik.GRF,
2012 Apr 29
1
CForest Error Logical Subscript Too Long
Hi,
This is my code (my data is attached):
library(languageR)
library(rms)
library(party)
OLDDATA <- read.csv("/Users/Abigail/Documents/OldData250412.csv")
OLDDATA$YD <- factor(OLDDATA$YD, label=c("Yes", "No"))?
OLDDATA$ND <- factor(OLDDATA$ND, label=c("Yes", "No"))?
attach(OLDDATA)
defaults <- cbind(YD, ND)
set.seed(47)
data.controls
2010 May 21
3
Concatenation
Hi,
I have a dataframe with some 800 rows and 14 columns.
Could you please advise how I can concatenate the rows - one after another.
Similarly for columns, one below the other.
Many thanks.
Cheers,
Santana
[[alternative HTML version deleted]]
2007 Aug 07
2
Spatial sampling problem
Hi All,
I am new in R and trying to simulate random normal 2D field with mean trend say north-south. My domain is 10x10 grid and I am trying to use mvnorm but do not know how to specify the domain and the mean field.
I would appreciate any help.
Cheers, SK
---------------------------------
[[alternative HTML version deleted]]