Displaying 20 results from an estimated 10000 matches similar to: "testing and ploting t-distribution"
2011 Mar 30
1
wrong calculation of R-squared in summary.lm
Dear all,
I just stumbled upon the fact, that when I perform a regression on
multivariate responses, that are not centred, I get a ricilulously high
R-squared value. After reading the code of summary.lm, I found a bug in
the function summary.lm:
mss is calculated by:
mss <-sum((f - mean(f))^2) - where f are the fitted values.
This works only for a single response variable, because
2006 Jun 30
1
Random numbers from noncentral t-distribution
Hi there:
I'd thought these two versions of noncentral t-distribution are essentially the same:
> qqplot(rt(1000,df=20,ncp=3),qt(runif(1000),df=20,ncp=3))
But, the scales of the x-axis and the y-axis are quite different according to the QQ-plot.
Did I make any mistakes somewhere?
Thanks,
Long
---------------------------------
2001 Sep 10
1
Multiresponse parameter estimation
I am looking for a way to do multiresponse parameter estimation for a
problem that is quite similar in form to the alpha-pinene example in Bates
and Watts (1988), p. 147, where the model is a set of ODEs. I am
specifically interested in obtaining the parameter covariance matrix, as
well. Which package(s) in R would I use to do such a thing?
Mark Schaffer
Dept. of Chemical Engineering
2013 Apr 27
11
Help
Hello,
I have a question and need your help urgently. I am new to R but want to learn it.
I have several files in a folder which I have imported to R using :
temp = list.files(pattern="*.txt")
>myfiles = lapply(temp, read.delim)
The resulting files are on the workspace stored as List[110]. So they are 110 files in the list. Each file has several different columns and rows.
My
2010 Oct 10
1
Create single vector after looping through multiple data frames with GREP
Hello all,
I changed the subject line of the e-mail, because the question I''m posing now is different than the first one. I hope that this is proper etiquette. However, the original chain is included below.
I've incorporated bits of both Ethan and Brian's code into the script below, but there's one aspect I can't get my head around. I'm totally new to programming
2009 May 19
2
problem with installing a local zip file : GFCURE
Dear all,
I am trying to install a package called "GFCURE" from a local zip file. This package fits a cure survival model and has been downloaded from:
http://post.queensu.ca/~pengp/software.html
The problem is that when I try to install this package from a local zip file using R, I've got the following error message:
Error in gzfile(file, "r") : cannot
2011 Mar 08
1
R Commander QQ Plot with triangular distribution
I am attempting to use the R Commander Graphs Quantile-Comparison
functionality on a dataset, to compare with a triangular distribution.
I have the package triangle. My question is on the syntax of how
to specify the parameters of the theoretical distribution in the
Parameters field of the dialog box. For example, the theoretical
distribution has min of 3000, max of 5000, mode of 4000. When
2010 Jun 16
2
Fitting Gamma distribution
I'm looking for goodness of fit tests for gamma distributions with large data
sizes and for different data.
I have a matrix with around 4.000 data values in it and i have fitted a
gamma distribution with "fitdistr".
You can see the example:
> fitdistr(corpo,"gamma",lower=0.001)
Errore in optim(x = c(5000, 5000, 5000, 5000, 5000, 5000, 5000, 5000,
5000, :
2006 Mar 23
1
Estimation of skewness from quantiles of near-normal distribution
I have summary statistics from many sets (10,000's) of near-normal continuous data. From previously generated QQplots of these data I can visually see that most of them are normal with a few which are not normal. I have the raw data for a few (700) of these sets. I have applied several tests of normality, skew, and kurtosis to these sets to see which test might yield a parameter which
2012 Jun 21
1
Distribution and location scale family
Hi,
For some dataset I have made a histogram, boxplot en qqplot.
http://r.789695.n4.nabble.com/file/n4634093/Naamloos.jpg
Investigate the data with the given functions for making QQ-plots and find
an appropriate location-scale family for the underlying distribution of this
sample. Apart from giving a proper location-scale family, also specify the
member of the location-scale family that is
2010 Oct 06
2
Converting scraped data
Dear Colleagues,
I used this code to scrape data from the URL conatined within. This
code should be reproducible.
require("XML")
library(XML)
theurl <- "http://www.queensu.ca/cora/_trends/mip_2006.htm"
tables <- readHTMLTable(theurl)
n.rows <- unlist(lapply(tables, function(t) dim(t)[1]))
class(tables)
test<-data.frame(tables, stringsAsFactors=FALSE)
2002 Nov 01
2
Empirical distribution
If some can help to find under wich package can i find the commando's
wich i schould to use to work with the empirical cummulative (ecdf)
distribution and also the QQplot.
Zmarrou Hicham
Univesity of Amsterdam
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r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info",
2011 Mar 30
1
sampling design runs with no errors but returns empty data set
Dear colleagues,
I'm working with the 2008 Canada Election Studies (http://www.queensu.ca/cora/_files/_CES/CES2008.sav.zip), trying to construct a weighted national sample using the survey package.
Three weights are included in the national survey (a household weight, a provincial weight and a national weight which is a product of the first two).
In the following code I removed variables with
2008 Mar 04
2
paired or one-sample t-Test
Hi Guys,
I am having a real hard time trying to figure out for microarry.
Here is my code
One-Sample t-Test
dim(data.sub)
[1] 10000 140 ##there are 10000 probesets and 140 columns
hist(data.sub) ## Histogram. Identify if the probesets are normal
distributed
q<-rnorm(10000) ##generate 10000 random, normal distributed values
qqplot(data.sub,q)) ##Show the plot of the probeset
2018 Jun 07
5
sys_setgroups failed on Solaris 11
Hi,
I'm trying to create a new Samba server to share files. We currently have an instance of Samba 3.6 on another server which we are using but need to retire that server.
I recently set up a new AD domain on Samba 4.3.11 on Ubuntu 16.04. There are two domain controllers. Most of the PCs are joined to this AD domain.
Our user accounts and group memberships are maintained in an LDAP
2018 Jun 07
2
sys_setgroups failed on Solaris 11
On Thu, 7 Jun 2018 17:28:43 +0200
Jean-Christophe Delaye via samba <samba at lists.samba.org> wrote:
> On 06/07/2018 04:04 PM, Teddy Brown via samba wrote:
> > Hi,
> > I'm trying to create a new Samba server to share files. We
> > currently have an instance of Samba 3.6 on another server which we
> > are using but need to retire that server.
> >
>
2011 Nov 05
1
testing significance of axis loadings from multivariate dudi.mix
Hi all
I?m trying to tests the significance of loadings from a ordination of 46 variables
(caategorical, ordinal and nominal). I used dudi.mix from ade4 for the ordination. A
years ago Jari Oksanen wrote this script implementing Peres-Neto et al. 2003 (Ecology)
bootstraping method:
netoboot <- function (x, permutations=1000, ...)
{
pcnull <- princomp(x, cor = TRUE, ...)
res
2012 Feb 10
1
making multiple lines using qqplot
Hi Everyone,
I want to make 3 lines on the same graph (not as subplots, all in the same
window, one on top of each other) and I want them to be quantile-quantile
plots (qqplot). Essentially, I am looking for the equivalent of Matlab's
"hold on" command to use with qqplot. I know I can use 'points' or 'lines',
but these do not give me a qqplot (only appear to work
2010 Jun 18
3
ploting dots with quentiles
http://r.789695.n4.nabble.com/file/n2260087/%E6%8D%95%E8%8E%B7.png
I am going to plot my data set like this, with means and 25% & 75%
quentiles.
I've tried "boxplot", but the output is not what I want. Should I use other
functions? Thanks
--
View this message in context: http://r.789695.n4.nabble.com/ploting-dots-with-quentiles-tp2260087p2260087.html
Sent from the R help
2003 Apr 29
4
thick plot lines
Dear People,
In a qqplot I am doing, I get lines/points that are very thick. I've tried
setting the lwd variable to 0.1, but it doesn't seem to have any effect.
Also, I have set the value of lty to dashed, but I still get dots. The
command looks like
qqplot(cdf.inv(seq(0,1,length=size),theta,pos,len),empmargdistvec(len,theta,pos,size),
xlim=c(-theta,theta), ylim=c(-theta,theta),