search for: varidable

Displaying 20 results from an estimated 106 matches for "varidable".

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2010 Oct 27
1
"non-numeric argument to binary operator" error while reading ncdf file
Hi everyone, I am a newbie in R and in this discussion list. I am trying to use R package "ncdf" to read values of temperature from a NCDF file. I did it before to another file using the function "get.var.ncdf", but now there is an error that I can not solve, and I would really appreciate if you could help me. I am using R version 2.11.1 (2010-05-31) in a machine with Linux
2010 Jun 18
2
varIdent error using gam function in mgcv
Hello, As I am relatively new to the R environment this question may be either a) Really simple to answer b) Or I am overlooking something relatively simple. I am trying to add a VarIdent structure to my gam model which is fitting smoothing functions to the time variables year and month for a particular species. When I try to add the varIdent weights to variable Month I get this error returned.
2005 Nov 03
1
Fitting heteroscedastic linear models/ problems with varIdent of nlme
Hi, I would like to fit a model for a factorial design that allows for unequal variances in all groups. If I am not mistaken, this can be done in lm by specifying weights. A function intended to specify weights for unequal variance structures is provided in the nlme library with the varIdent function. Is it apropriate to use these weights with lm? If not, is there another possibility to do
2007 Aug 07
0
Bug in coef<-.varIdent method (nlme package) (PR#9831)
Hello, 1. It appears that "coef<-.varIdent" method does not work properly in some instances. Execution error: Error in `coef<-.varIdent`(`*tmp*`, value = c(11, 12)) : Cannot change the length of the varIdent parameter after initialization occurs when "coef<-.varIdent" is applied to an initialized object of class varIdent with some of the coefficients
2007 Jun 01
2
how to specify starting values in varIdent() of lme()
I was reading the help but just did not get how to specify starting values for varIdent() of the lme() function, although I managed to do it for corSymm(). Do I specify the values just as they are printed out in an output, like c(1, 1.3473, 1.0195). Or do I need to take the residual and multiply it with these like c(0.2235, 0.2235*1.3473, 0.2235*1.0195) or any other form that I dont know of?
2010 Nov 05
0
NaN, ncdf
Dear All, Can anyone please let me know how exactly ncdf deals with NaN. I am trying to pass in a vector of data that has some NaN in it, into a variable in NetCDF. dimX <- dim.def.ncdf("X","count",(1:6)) dimY <- dim.def.ncdf("Y","count",(1:3)) var1 <-
2007 Jun 10
1
{nlme} Multilevel estimation heteroscedasticity
Dear All, I'm trying to model heteroscedasticity using a multilevel model. To do so, I make use of the nlme package and the weigths-parameter. Let's say that I hypothesize that the exam score of students (normexam) is influenced by their score on a standardized LR test (standLRT). Students are of course nested in "schools". These variables are contained in the
2012 Aug 28
4
[ncdf4] error converting GEIA data to netCDF
summary: I can successfully ncvar_put(...) data to a file, but when I try to ncvar_get(...) the same data, I get > Error in if (nc$var[[li]]$hasAddOffset) addOffset = nc$var[[li]]$addOffset else addOffset = 0 : > argument is of length zero How to fix or debug? details: R code @ https://github.com/TomRoche/GEIA_to_NetCDF successfully (if crudely) uses R packages={ncdf4, maps, fields}
2007 Sep 27
1
Getting intervals for within-group standard errors for each group using nlme and varIdent
I am using lme from the nlme package to fit a mixed model. We have observations nested in patients(encounters) and patients nested in groups (2 different treatments). We are interested in the differences between the 2 groups, both the means and the standard deviations (are patients in group A less variable than those in group B? both within patient and between patient within group). Here is
2009 Feb 24
1
Initialize varFunc in R
Hi, I am running R2.8.1 under Linux, and I am having trouble using the variance functions in nlme My basic model was something like: model0 <- lme( log(growth) ~ light * species.group , data=data, random=~light|species ) # with 20 odd species divided in 2 groups Following the methods in Pinheiro&Bates I tried to put a variance function in the model: model1 <- update(model0,
2008 Jul 09
1
netCDF to TIFF
Greetings R users! I am working with the ENSEMBLE climate data (10 min resolution daily temperatures images for all of Europe 1950-2006). The data comes packaged in a single netCDF file. I would like to read the data in and export a subset (2002-2006) as geotiffs (one image per day). So far, I can successfully read in the data and view the images within an R display window. However, I have yet to
2006 Sep 20
1
variance functions in glmmPQL or glm?
Hello R users- I am new to R, and tried searching the archives and literature for an answer to this - please be patient if I missed something obvious. I am fitting a logistic regression model, and would like to include variance functions (specifically the varIdent function). I cannot figure out how to do this either in glmmPQL (or something similar) for the model with random effects, or in glm
2012 Jul 23
2
translating IDL to R
I would appreciate * guidance regarding translation of IDL routines to R, generally * assistance translating two IDL routines to R, specifically Why I ask: I'm slowly learning how to do atmospheric modeling. One language that has been been popular in this space is IDL http://en.wikipedia.org/wiki/IDL_(programming_language) which unfortunately is proprietary (not to mention butt-ugly, IMHO
2016 Apr 22
2
Unexpected values obtained when reading in data using ncdf and ncdf4
Dear R Users, I am encountering a problem when reading nc files into R using the ncdf and ncdf4 libraries. The nc files are too large to attach an example (but if someone is interested in helping out I could send a file privately via an online drive), but the code is basic: for(i in 1:length(thesenames[,1])){ data <- nc_open(paste(INDIR, thesenames[i,c("wholename")],
2006 Jul 17
1
Variance functions in package nlme
Dear R-help, I am trying to set up linear mixed effects models in R using the (recommended) nlme package (R version 2.3.1 on a Linux platform). When trying to reproduce an example from Jose Pinheiro & Douglas Bates (2000, p 210) I get the following error message (code to produce message pasted as well): library("nlme") data("Orthodont") vf1Ident <- varIdent(
2011 May 21
1
predict.gls choking on levels of factor
I've got a gls formula that's a mix of continuous and ordered variables. I wanted to use gls because I wanted to use the varIdent structure. Anyway, attempts to use "predict.gls" choke with the error that the levels I use are not allowed for one of them -- the first one alphabetically, so I'd guess the second would have the same problem. So I have three linked questions --
2002 Aug 29
8
lme() with known level-one variances
Greetings, I have a meta-analysis problem in which I have fixed effects regression coefficients (and estimated standard errors) from identical models fit to different data sets. I would like to use these results to create pooled estimated regression coefficients and estimated standard errors for these pooled coefficients. In particular, I would like to estimate the model \beta_{i} = \mu +
2004 Jul 12
2
lme unequal random-effects variances varIdent pdMat Pinheiro Bates nlme
How does one implement a likelihood-ratio test, to test whether the variances of the random effects differ between two groups of subjects? Suppose your data consist of repeated measures on subjects belonging to two groups, say boys and girls, and you are fitting a linear mixed-effects model for the response as a function of time. The within-subject errors (residuals) have the same variance in
2011 Sep 07
1
Error: in routine alloca() there is a stack overflow: thread 0, max 535822282KB, used 0KB, request 24B
Dear Colleagues: Through your help an R related installation issue was resolved, but I now have the following usage issue. On any "get.var.ncdf" usage I am seeing: Error: in routine alloca() there is a stack overflow: thread 0, max 535822282KB, used 0KB, request 24B The same error is posted on a file as small as 50MB and as large as 500GB, with ulimit set to unlimited. I
2010 Apr 14
2
GAMM : how to use a smoother for some levels of a variable, and a linear effect for other levels?
Hi, I was reading the book on "Mixed Effects Models and Extensions in Ecology with R" by Zuur et al. In Section 6.2, an example is discussed where a gamm-model is fitted, with a smoother for time, which differs for each value of ID (4 different bird species). In earlier versions of R, the following code was used BM2<-gamm(Birds~Rain+ID+