Displaying 20 results from an estimated 1000 matches similar to: "covariance analysis model"
2009 Apr 20
7
Fitting linear models
I am not sure if this is an R-users question, but since most of you here
are statisticians, I decided to give it a shot.
I am using the lm() function in R to fit a dependent variable to a set
of 3 to 5 independent variables. For this, I used the following
commands:
>model1<-lm(function=PBW~SO4+NO3+NH4)
Coefficients:
(Intercept) SO4 NO3 NH4
0.01323 0.01968
2008 Nov 18
1
Tukey HSD following lme
Hi everyone
I'm using Tukey HSD as post-hoc test following a lme analysis. I'm
measuring hemicelluloses in different species treated with three
different CO2 concentrations (l=low, m=medium, h=high). The whole
experiment is a split-plot design and the Tukey-function from the
package multcomp is suitable for lme-analysis with random factors.
The analysis works fine but I get a non
2009 Sep 11
1
format (?) problems with data imported from postgres
Good day,
I read some data from a PostgreSQL database by a following script:
library(Rdbi)
library(RdbiPgSQL)
# conn becomes an object which contains the DB connection:
conn <- dbConnect(PgSQL(), host="localhost", dbname="BVS",
user="postgres", password = "*******")
query_duj_kal <- dbSendQuery(conn, "select zdroj as well, cas as date,
fe2,
2009 Jul 25
1
yaxp problem for more irregular time series in one plot
Good day,
I'm trying to get more time series in one plot. As there are bigger
differences in values of variables I need logaritmic y axis.
The code I use is the following:
nvz_3_data <- read.csv('/home/tomas/R_outputs/nvz_3.csv')
date <- (nvz_3_data$date)
NO3 <- (nvz_3_data$NO3)
NH4 <- (nvz_3_data$NH4)
date_p <- as.POSIXct(date, "CET")
par(mfrow=c(2,1), ylog
2010 Jul 23
2
re-ordering bwplot
Dear list:
I'm using bwplot to compare concentrations by location and treatment as in:
# using built in data
bwplot( conc ~ Type : Treatment, data = CO2 )
I would like the order of the plots to be: 3,4,1,2. I can't seem to figure this out with index.cond or permc.cond.
Any help is appreciated!
Brad Eck
[[alternative HTML version deleted]]
2009 Sep 13
2
zoo plot: yearly marks on X-Axis
On Sun, 2009-07-26 at 13:17 +0200, Poersching wrote:
> stvienna wiener schrieb:
> > Hi all,
> >
> > I am plotting a financial time series, but I need a more detailed X-Axis.
> >
> > Example:
> > x <- zoo(rnorm(1:6000), as.Date("1992-11-11")+c(1:6000))
> > plot(x)
> >
> > The X-Axis is labeled "1995", "2000"
2013 Apr 26
2
Remove reciprocal data from a grouped animal social contact dataset
Hi r-help forum,
I have been collecting contact data (with proximity logger collars)
between a few different species of animal. All animals wear the
collars, and any contact between the animals should be detected and
recorded by both collars. However, this isn't always the case and more
contacts may be recorded on one collar of the two. This is fine, it
depends on battery life and other
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
2008 Aug 21
1
summary.lme and anova question
Dear all,
When analyzing data from a climate change experiment using linear mixed-effects models, I recently
came across a situation where:
- the summary(model) showed a significant difference between the levels of a two-level factor,
- while the anova(model) showed no significance for that factor (see below).
My question now is: Is the anova.lme() approach correct for that model? And why does
2005 May 14
1
make check fails after building R 2.1.0 on Fedora Core 3
I have R v2.0.1 already running on the machine in question; a fairly
generic Fedora Core 3 machine. I am trying to build the new version
2.1.0 and have not been able to troubleshoot the problem I encountered.
I'm hoping someone else has seen it and can suggest a troubleshooting
avenue to me.
The build succeeds, both from the source RPM and from the tarball. I
believed I had all the build
2008 Dec 23
2
beginner data.frame question
I need some help understanding how on of the example data sets is
formatted in the basic R installation. If I load the Mona Loa CO2
data, with the command:
> data(co2)
I can view the data with:
> co2
And the data are in the form of 11 rows labeled as years (1994-2004)
and 12 columns labeled (Jan - Dec). This structure appears to be a
dataframe, however, if I type the command
2009 Mar 22
1
Multiple Comparisons for (multicomp - glht) for glm negative binomial (glm.nb)
Hi
I have some experimental data where I have counts of the number of
insects collected to different trap types rotated through 5 different
location (variable -location), 4 different chemical attractants [A, B,
C, D] were applied to the traps (variable - semio) and all were
trialled at two different CO2 release rates [1, 2] (variable CO2) I also
have a selection of continuous variables
2004 Jan 22
1
spectrum
Dear R users
I have two questions about estimating the spectral power of a
time series:
1) I came across a funny thing with the following code:
data(co2)
par(mfrow=c(2,1))
co2.sp1<-spectrum(co2,detrend=T,demean=T,span=3)
co2.sp2<-spectrum(co2[1:468],detrend=T,demean=T,span=3)
The first plot displays the frequencies ranging from 0 to 6
whearas the second plot displays the same curve but
2007 Jun 19
1
help w/ nonlinear regression
Dear All,
I'd like to fit a "kind" of logistic model to small data-set using nonlinear least-squares regression. A transcript of R-script are reproduced below. Estimated B and T (the model's coeff, herein B=-8,50 and T=5,46) seem appropriate (at least visually) but are quite diff from those obtained w/ SPSS (Levenberg-Marquardt): B=-19,56 and T=2,37. Am I doing something wrong in
2003 Sep 09
2
Making R packages (Unix)
Hi:
I have have taken over from a colleague who
prepared an R package and failed to build it on
Windows. I am doing this with unix as I am a mac
user. Below is the output I get when I use the
build command:
[gattuso:unix/R/CO2.Rcheck] gattuso% R CMD build CO2
* checking for file 'CO2/DESCRIPTION' ... OK
* preparing 'CO2':
* checking whether 'INDEX' is up-to-date ...
2008 Jan 15
2
Cannot configure wine/darwine
I've installed Darwine on an iMac. As per the
documentation, I have attempted to run winecfg to set
the various configs. But I cannot get it to display.
The error log says that it attempted to create a
window, but no driver found. Since I can't config, I
can't set a driver.
Any ideas?
Richard
Photography by:
Richard Barnard
3501 Thomas Rd.; Suite 13
Santa Clara, CA 95054
408
2007 Jun 04
3
test for nested factors
Is there a conventional way to test for nested factors? I.e., if 'a'
and 'b' are lists of same-length factors, does each level specified by
'a' correspond to exactly one level specified by 'b'?
The function below seems to suffice, but I'd be happy to know of a more
succinct solution, if it already exists.
Thanks,
Tim.
---
"%nested.in%" <-
2011 Oct 09
1
sapply(pred,cor,y=resp)
Hello. I am wondering why I am getting NA for all in cors=sapply(pred,cor,y=resp). I suppose that each column in pred has NAs in them. Is there some way to fix this? Thanks
> str(pred)
'data.frame': 200 obs. of 13 variables:
$ mnO2: num 9.8 8 11.4 4.8 9 13.1 10.3 10.6 3.4 9.9 ...
$ Cl : num 60.8 57.8 40 77.4 55.4 ...
$ NO3 : num 6.24 1.29 5.33 2.3 10.42 ...
$ NH4 : num 578
2006 Oct 23
1
Color eps/ps output from specialized plots?
Hello,
First a disclaimer :) I am very new to using R.
I am generating some plots and eventhough I can get colored output in the encapsulated postscript files in the simplest of commands (e.g. plot(1:10,1:10, type="l", col="red") ), it does not work for the particular plots I want. It works on the screen.
Here is an example taken out from "Mixed-Effects Models in S and
2012 Nov 12
2
Using "apply" instead of "for" loop / multithreading
Hello ,
I'm new to R and don't really understand how to use the function "apply"
instead of a "for loop", particularly for a function with multiple entries.
I have a big data file and would like to apply a function in multi thread to
accelerate the processus.
I have a data frame containing values of* CO2 in ppm (resp[i,6])* that I
want to convert in umol of CO2