Displaying 20 results from an estimated 100 matches similar to: "how to avoid a for looping break after an error message"
2007 Aug 22
1
distance by vegan
How to calculate sorensen (bray-curtis) distance by dist function
within the vegan package?
Cheers
Duccio
2007 Oct 22
3
Spatial autocorrelation
Hi,
I have collected data on trees from 5 forest plots located within the
same landscape. Data within the plots are spatially autocorrelated
(calculated using Moran's I). I would like to do a ANCOVA type of
analysis combining these five plots, but the assumption that there is no
autocorrelation in the residuals is obviously violated. Does anyone have
any ideas how to incorporate these spatial
2008 Sep 25
1
Confusion over syntax in a package
Hello,
I am new to R and I am attempting to use the ProbForecastGOP package
for some research I am conducting.
The package works fine when I call the functions from the command line
as the examples instruct.
However, I am attempting to step through some of the functions so that
I can obtain a better idea of what is going on. I have come to the
following command:
2013 Jan 31
2
Writing audio files (.wav) in a different directory
Hi.
I'm trying to export a .wav file using the writeWave function from tuneR
package in a different folder than the default getwd().
After reading through the manuals of some audio packages I couldn't figure
it out.
I'm picking one 3-hour .wav file and asking the function to take a sample
of 1 minute (from minute 100 to minute 101 of the 3-hour file) and saving
it in an object
2006 Jul 18
2
Using corStruct in nlme
I am having trouble fitting correlation structures within nlme. I would like to
fit corCAR1, corGaus and corExp correlation structures to my data. I either
get the error "step halving reduced below minimum in pnls step" or
alternatively R crashes.
My dataset is similar to the CO2 example in the nlme package. The one major
difference is that in my case the 'conc' steps are
2006 Jul 01
1
nlme: correlation structure in gls and zero distance
Dear listers,
I am trying to model the distribution of fox density over years in the
Doubs department. Measurements have been taken on 470 plots in March
each year and georeferenced. Average density is supposed to be different
each year.
In a first approach, I would like to use a general model of this type,
taking spatial correlation into account:
2010 Apr 14
1
creating a new corClass for lme()
Hi,
I have been using the function lme() of the package nlme to model grouped
data that is auto-correlated in time and in space (the data was collected on
different days via a moving monitor). I am aware that I can use the
correlation classes corCAR1 and corExp (among other options) to model the
temporal and spatial components of the auto-correlation. However, as far as
I can tell, I can only
2012 Aug 29
1
spatial correlation in lme and huge correlation matrix (memory limit)
Hi,
I'm trying to introduce a (spatial) exponential correlation
structure (with range=200 and nugget.effet of 0.3) in a lme model of
this form: lme(ARBUS~YEAR, random=~1|IDSOUS).
The structure of the data is "IDSOUS" "XMIN" "YMAX" "YEAR" "ARBUS"
with 2 years of data and 5600 points for each year.
I do:
2012 May 02
3
Consulta gráfica
Hola,
Por favor, ¿podríais indicarme qué recursos (librerías o ideas) pueden resultar de utilidad para crear un gráfico del estilo del de la figura 3.8 del siguiente link?
http://www.tsc.uvigo.es/BIO/Bioing/ChrLDoc3.html#3.5
Actualmente estoy utilizando funciones muy básicas y la verdad es que no me encuentro muy satisfecha con el resultado.
Muchas gracias.
Eva
[[alternative HTML
2004 Sep 24
1
exponential correlation?
Hello,
I have been asked to perform a exponential correlation on a data set.
Unfortunately, i did not find any simple example on how to do that with R.
If the correlation is significant, one asked me to also find the thresold
of the acceleration slope.
Have any of you a little example or a good link to get me started?
Best regards
Blaise
--
Mutt, c'est de la balle, quand ??a marche :-)
2011 May 27
1
continuous time AR(1)
Dear R helpers,
I would like to model temporal trend of biological remains in sediment cores.
All samples are temporally auto-correlated and I would like to take this effect
into account.
Initially I thought that I could use AR(1) or ARIMA functions but these
functions only work with regular temporal intervals between samples.
Hence I would like to use a continuous time AR(1) that allow
2008 Sep 27
1
seg.fault from nlme::gnls() {was "[R-sig-ME] GNLS Crash"}
>>>>> "VW" == Viechtbauer Wolfgang (STAT) <Wolfgang.Viechtbauer at STAT.unimaas.nl>
>>>>> on Fri, 26 Sep 2008 18:00:19 +0200 writes:
VW> Hi all, I'm trying to fit a marginal (longitudinal)
VW> model with an exponential serial correlation function to
VW> the Orange tree data set. However, R crashes frequently
VW>
2005 Mar 22
2
LME correlation structures: user defined
Let me modify my question about user-defined covariance structures for LME models: Can somebody tell me how I can see the code for the definition of the correlation structures that come with the NLME package. Specifically I like to see the code for the functions coef, corMatrix, and intialize for any of the pre-defined correlation structures, and use this as a template to define a new correlation
2009 Sep 01
1
understanding the output from gls
I'd like to compare two models which were fitted using gls, however I'm
having trouble interpreting the results of gls. If any of you could offer
me some advice, I'd greatly appreciate it.
Short explanation of models: These two models have the same fixed-effects
structure (two independent, linear effects), and differ only in that the
second model includes a corExp structure for
2004 Sep 22
1
impenetrable warning
Dear R-help,
Can anyone explain the meaning of the warning,
Singular precision matrix in level -1, block 1
? Or how to track down where it comes from?
More precisely, using the nlme package, I'm issued with the warning
itt2 <- lme(lrna~rx.nrti+lbrna, random=~1|patid,
cor=corExp(form=~days|patid,nugget=T), weights=varPower(
form=~lbrna),data=rna3)
Warning messages:
1: Singular
2008 Mar 19
1
analyzing binomial data with spatially correlated errors
Dear R users,
I want to explain binomial data by a serie of fixed effects. My problem is
that my binomial data are spatially correlated. Naively, I thought I could
found something similar to gls to analyze such data. After some reading, I
decided that lmer is probably to tool I need. The model I want to fit would
look like
lmer ( cbind(n.success,n.failure) ~ (x1 + x2 + ... + xn)^2 ,
2011 Dec 16
1
Model design
Dear List,
I am realtively inexperienced so i apologise in advance and ask for
understanding in the simplicity of my question:
I have data on the amount of grass per km in a cell ( of which i have
lots) "grass" and for each cell i have x/y coordinates - required due
to spatial autocorrelation
Cells can be classfied in a hierarchical nature into AREAS and STATES
i.e Cell 1, Cell 2,
2008 Oct 10
1
glmmPQL
Dear all,
I am experiencing problems with glmmmPQL. I am trying to analyze
binomial data with some spatial autocorrelation. Here is my code and
some of the outputs
> colnames(d.glmm)
[1] "BV" "Longitude" "Latitude" "nb_pc_02" "nb_expr_02"
[6] "pc_02" "nb_pc_07" "nb_expr_07"
2009 Sep 22
1
odd (erroneous?) results from gls
A couple weeks ago I posted a message on this topic to r-help, the response
was that this seemed like odd behavior, and that I ought to post it to one
of the developer lists. I posted to r-sig-mixed-models, but didn't get any
response. So, with good intentions, I decided to try posting once more, but
to this more general list.
The goal is (1) FYI, to make you aware of this issue, in case it
2011 Apr 06
1
corSpatial and nlme
I noticed that ?corClasses in package nlme does not list corSpatial among the standard classes. This might either be intentional because corSpatial is not "standard" , or it might be simply an oversight that needs correcting.
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Robert W. Baer, Ph.D.
Professor of Physiology
Kirksville College of Osteopathic Medicine
A. T. Still University of