Displaying 16 results from an estimated 16 matches for "semivariogram".
2007 Jan 05
1
gstat package. "singular" attibute
Hello,
I'm using the gstat package within R for an automated procedure that
uses ordinary kriging.
I can see that there is a logical ("singular") atrtibute of some
adjusted model semivariograms:
.- attr(*, "singular")= logi TRUE
I cannot find documentation about the exact meaning and the implications
of this attribute, and I dont know anything about the inner calculations
of model semivariograms.
I guess that the inverse of some matrix need to be calculated , and
this matri...
2007 Oct 08
1
semivariogram
I need the most straightforward way to build semivariograms within R
i am currently using s-gems software but i would like to even test R
Thanks
D
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2006 Aug 20
3
plot problem
Hello.
I'm pretty much new to R and I'm trying to produce some figures.
It seems to me, that R has some asynchronous way of plotting figures.
When I run this code:
#constructs the semivariogram of SC1929
vgm1 <- variogram(SC1929~1,~U+V,puerto.map$att.data)
# trying to make new plot
dev.set(which=dev.next())
plot(vgm1)
title(main="Semivariogram",font.main=4)
dev.copy2eps(file="fig2.eps",horizontal=T)
dev.off()
R complains that
Error in title(main = "Semivariog...
2005 Nov 08
2
Variogram
Dear All,
Is there anybody has the experience in using variogram(gstat) ? Please kindly give me some hints about the results.
I used variogram() to build a semivariogram plot as:
tr.var=variogram(Incr~1,loc=~X+Y,data=TRI2TU,width=5)
then fir the variogram to get the parameters as:
v.fit = fit.variogram(tr.var,vgm(0.5,"Exp",300,1))
v.fit
model psill range
1 Nug 1.484879 0.00000
2 Exp 3.476700 29.70914
This is the output of v.fit. Can any...
2008 Aug 05
4
LIDAR Problem in R (THANKS for HELP)
...I am a brand-new in R and geostatistic (SORRY, my
background it?s in forestry) but I wish improve my skill for improve myself.
I wish to develop a methodology to processing a large data-set of points
(typical in LiDAR) but there is a problem with memory. I had created a
subsample data-base but the semivariogram is periodic shape and I am not to
able to try a fit the model. This is a maximum of two weeks of work (day bay
day) SORRY. Is there a geostatistical user I am very happy to listen his
suggests. Data format is X, Y and Z (height to create the DEM) in txt format
I have this questions:
1. A...
2010 Nov 17
1
Please, help me with 'mattern' variogram
...sistema es computacionalmente singular: n?mero de condici?n rec?proco = 1.05091e-159
I also wander if there is any limit for kappa. Which one would be the maximun. As far as I'm concerned, it must be always major than cero, right?. I also know that its values depend on the tendency of cloud semivariogram, if it flattens slowly (Gaussian) it's major.
I'll thank the one available to answer my desperate question.
2008 Apr 29
2
Variogram problem
...aim to carry out an interpolation by krigeage. My goal is to obtain
a chart of the distribution of precipitations/temperatures in Europe
starting from 73 different stations (and, of course, distributed irregularly
on the chart, where use of the krigeage). Here, I carried out this to test
to obtain semivariogram spherical by groping:
x<-ts(rnorm(73))
cs1<-corSpher(form=~x)
y<-Variogram(cs1,2628) #2628 corresponding to the " distance" described in
l' helps, that is to say the number of station* (the number of station -1)
/2.
But there does not go it misses apparently much d'...
2006 Aug 15
4
nls
Is there anyway to change any y[i] value (i=2,...6) to make following NLS workable?
x <- c(0,5,10,15,20,25,30)
y <- c(1.00000,0.82000,0.68000,0.64000,0.66667,0.68667,0.64000)
lm(1/y ~~ x)
nls(1/y ~~ a+b*x^c, start=list(a=1.16122,b=0.01565,c=1), trace=TRUE)
#0.0920573 : 1.16122 0.01565 1.00000
#Error in numericDeriv(form[[3]], names(ind), env) :
# Missing value or
2005 Dec 21
0
Help with Krige.conv using linear models
A majority of my data makes a kriged map perfectly using an exponential
model for the semivariogram to fit my data and then going through the
commands variofit() to define the model and then krige.conv() to use the
model to predict values in a grid. But?one set of my data appears to be
linearly correlated for the first 5000 meters and not correlated beyond
that. I have been having problems u...
2006 Jun 28
1
calculating the spacial autocorrelation for poisson data
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2008 Jul 31
1
anisotropy in vgm model. HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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2008 Jul 20
2
Indicator Kriging?
Hello All!
I like to do some indicator kriging with R.
So far I used geoR for simple and ordinary kriging.
Does anybody know which package I should use?
Thanks for your help!
Sascha!
--
Jetzt dabei sein: http://www.shortview.de/wasistshortview.php?mc=sv_ext_mf at gmx
2012 Jul 31
2
Spatial regression
Dear list members,
I have a large dataset with point data. Each data point has X, Y, number of
species present and values for one single explanatory variable. Each point
was generated from a polygon grid shapefile and they are at equal
distances.
I conducted GLS analyses introducing variance structures and correlation
structures to improve the model.
I plotted variograms before and after adding
2012 Oct 01
0
glmmPQL and spatial autocorrelation
...g
into my model. I am trying to model the presence of dives (versus simulated
pseudo-absences) using a binomial generalized binomial model (glmmPQL),
since I can incorporate the autocorrelation structure to the model using
that package. However, I'm trying to come up with ways to evaluate which
semivariogram is the most adequate for my model, but not having AICs
complicated things a bit for me. Any suggestions on how to best achieve
this?
Thanks in advance
----------------------------------------
Luis A. Huckstadt, Ph.D.
Department of Ecology and Evolutionary Biology
University of California Santa Cru...
2005 Jan 01
1
lme: Variances
Hi R users!
I will try to state my question again. I have longitudinal data and fitted the
following model with lme:
Y = X*beta + U + W(t) + Z
where
U ~ N(0, nu*I) I is the identity matrix, so this is the random intercept
W(t)~ N(0, sigma*H) and H is a matrix which incorporates a Gaussian serial
correlation (covariance) in the offdiagonal
2010 Sep 16
4
Pesky homemade function code
Hi all-
this seems to be simple to figure out but since im new to writing functions
I dont know what is happening. Here is my code along with the error I am
receiving:
semivario=function(data,ids,times,resids){
id=unique(data$ids)
index=combinations(length(data$times[data$ids==id[1]]),2)
time=gamma=numeric(dim(index)[1])
for (j in 1:dim(index)[1]){