Displaying 20 results from an estimated 300 matches similar to: "Variogram problem"
2017 Sep 24
1
R version 3.3.2, Windows 10: gstat package: Error in fitting a variogram model using 'fit.variogram' function
Dear Members,
I am trying to fit a variogram model using fit.variogram function from the gstat package. The figure showing my experimental variogram can be seen here: https://i.stack.imgur.com/UZXw4.png
My code line for this operation is:
> c2.vgm.fit<-fit.variogram(c2.vgm.exp,vgm(nugget=0, psill=400,model="Exp",range =40000),fit.method = 7)
The system throws following error
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
2009 Mar 24
1
Variogram with Gstat
Dear all can you help me? i have this problem: i have a dataset in a text file
in a matrix of 3 columns: x, y, z where x and y are the coordinates and Z are
the mesurements. How can i do a variogram with R?
2008 Jun 04
1
problems with variogram
Hello,
I have data at 10 locations, in each location there are time series
(T=56). Question is: when I?m fitting variogram what happens with those
measures in each location? Are they taken as repeated measures? It's very
important for my to know this
Thanks a lot
2006 Jun 03
1
default value for cutoff in gstat variogram()
I wonder what is the default value for the argument 'cutoff' when not
specified in the variogram.formula function of gstat. Computing
variogram envelops within gstat, I am comparing the results obtained
with variog in geoR and variogram in gstat, and it took me a while
before understanding that the cutoff default value is not the maximum
distance.
Can Edzer tell us about it?
All the
2011 Feb 18
0
Variogram (nlme) of a lme object - corSpatial element question
Dear Users,
>From previous analysis (semi-variograms using package gstat), I found
spatial autocorrelation in my dataset.
The best fitted model to this spatial correlation structure is the Gaussian
model (Spherical, Exponential, Linear tested and comparison done by Sum of
Square errors).
So I used corGaus function to define this spatial autocorrelation in my lme
model using the option
2012 Apr 13
0
Geostatitics 3D Variogram Map
Dear R Helpers
I'm investigation the geostatistics tools in R and have found the package 'gstat', which looks to be useful four two dimensional data. However, I usually deal with three dimensional information. I would like to compute a 3D variogram map using the variogram tool but cannot seem to get it to recognise the third (z) dimension
The data file reads ok and the spatial
2006 Mar 13
2
Error Message from Variogram.lme Example
When I try to run the example from Variogram with an lme object, I get
an error (although summary works):
R : Copyright 2005, The R Foundation for Statistical Computing
Version 2.2.1 (2005-12-20 r36812)
ISBN 3-900051-07-0
...
> fm1 <- lme(weight ~ Time * Diet, BodyWeight, ~ Time | Rat)
Error: couldn't find function "lme"
> Variogram(fm1, form = ~ Time | Rat, nint =
2011 Feb 18
0
Bug in the function Variogram (package nlme) ?
Dears UseRs,
In Zuur's book (Mixed effects models and extensions in ecology with R), p
167, it is mentionned that the Variogram function (package nlme) scale the
sill to 1.
Here is the plot of the semi-variogram given by the Variogram function on my
"lme" object. (http://imm.io/3OLe)
Note that the semi-variance exceed 1 !!
It can probably explain why the Gaussian correlation
2004 Oct 25
1
sample variogram construction
Hi
Im attempting to build a sample variogram for 300 obersvations
of longitudinal data. So what I need to do is compute the half
squared differences between pairs of residuals (for instance
if a subject has 4 obersvations, this is 4 choose 2 paird differences)
for each subject.
Also, then I need the corresponding time differences within each
individual. So the end result will be a 300 by 2
2000 Oct 20
1
Covariace or variogram surface
Hi
I'm interested in doing a anisotropy analysis of some spatial data and I
want to do a contour plot of a covariance or variogram surface to
visualize the directions of maximal and minimal anisotropy.
I know how to do a contour plot :-) but how can I obtain the variogram
surface having a geoeas format dataset (X, Y, Z) ?
Thanks
EJ
2005 Jun 24
2
definition of variogram
hello
I need basic explanation of variogram
and how to use in R.
I will appreciate if you supply them.
regards
Ahmet Temiz
______________________________________
XamimeLT - installed on mailserver for domain @deprem.gov.tr
Queries to: postmaster at deprem.gov.tr
______________________________________
The views and opinions expressed in this e-mail message are ...{{dropped}}
2009 Oct 08
1
variogram
Hello everybody,
I want to run the following R-code, but it does'nt work.
> res.vgm = variogram(ertrag ~ rep, # !!!
+ loc = ~ xpos + ypos, # !!!
+ width = start.range / 10,
+ data = d)
Error in vector("double", length) : element 2 is empty;
the part of the args list of '.Internal' being evaluated was:
2011 Mar 25
1
spatial stats - geoR - variogram - standard deviation
Hello,
I am attempting to get the standard deviation in multiple distance bins in
my spatial data.
It appears as though the 'variog' command in the geoR package will do the
trick, as one of the outputs from 'variog' is 'variog$sd', which,
according to the manual, is the "standard deviation of the values in each
bin".
However, when I run this command, the
2010 Jun 09
0
Fixed sill in variogram fitting (geoR)
Dear all,
I'm trying to fit a variogram model using variofit function in geoR
package. There is an option to fix the nugget but is there anyway to force
the variogram sill to equal some defined value? I'm working with
standardized longitudinal data so the process variance is 1 and I'd like
to force the sill of the variogram to reach this value (and prevent it
from going
2002 Nov 19
0
Help on variogram.gls (nlme package)
I am trying to use the nlme package in R following the book
"Mixed-Effects Models in S and S-Plus". I have the latest versions of R
(1.6.1) and nlme (3.1-33) for Windows (95 or later).
I had problems with the instruction Variogram using a gls class object
(Section 5.4, pg 261-262). Even when I use the scripts included in the
package, I get an error message and not the expected
2009 Jun 11
0
Variogram fitted by Cauchy
Hi
I'm using R(2.9.0) and gstat package under Windows to plot sample variograms.
When I want to fit them, I don't have the possibility to choose Cauchy functions. Under Mathematica for example, we have it and it seems to be the best one to fit the variograms I have
I tested the others functions, they can fit but I would,if possible, use the Cauchy one. If anybody knows something about
2012 Nov 24
0
Grouped data objects within GLS and Variogram
Dear R Help,
I am having difficulty using Variogram within GLS to examine spatial structure of nested data. My data frame consists of ecological measurements of a forest, in which three landscape positions ("landposi") are compared. Each landscape position is replicated five times ("replicat"), and the environment is measured ("canopy", "litdepth", etc.)
2003 Sep 10
1
geoR variogram problem
Dear GeoR-er,
If I use the variog function in the latest release of geoR, the first lag is
always ignored.
For instance, if you read in geodata, calculates the variogram using the
variog function and give in a uvec like uvec=seq(0,max,by=2.44), it only
starts giving results from distance=4.88 and ignores 2.44!
This wasn't the case in former versions of geoR. Is this done on purpose?
Why?
2011 Jan 23
0
Madogram, rodogram, semi-variogram of satellite imagery
Greetings!
Is there in any package for R which can help me generate madogram, rodogram,
semi-variogram, cross variogram from landsat imagery. I intend to select
portions of large imagery (i.e., obtain subsets) and generate the above said
texture layers. A simple Google search led to me a result suggesting
SpatialExtremes for generating madograms. However I am not sure about its
capability to