Displaying 20 results from an estimated 4000 matches similar to: "(no subject)"
2007 May 19
1
clustered standarderrors using design package
Please help,
I have a strange problem. I've got a balanced panel data set. I use dummy
variable regression and I've got results with lm function.
summary(lm(y ~ post + t19961 + t19962 + t19963 + t19964 + t19971 + t19972
+ t19973 + t19974 + t19981+factor( id)))
The problem is that I would like to get my standard errors clustered but
then gets the following error message:
f<-(lm(y ~
2006 Sep 15
2
prediction interval for new value
Hi,
1. How do I construct 95% prediction interval for new x values, for example - x = 30000?
2. How do I construct 95% confidence interval?
my dataframe is as follows :
>dt
structure(list(y = c(26100000,
60500000, 16200000, 30700000, 70100000, 57700000, 46700000, 8600000,
10000000, 61800000, 30200000, 52200000, 71900000, 55000000, 12700000
), x = c(108000, 136000,
2009 Jul 03
2
Two questions about the cloud function in the lattice package
Hi,
I have two questions regarding the cloud function in the lattice
package:
1) Is there a way to not print the surrounding frame (i.e. the square
surrounding the entire plot)?
2) Is there a way to italicize the text displayed with the key argument?
Some sample code:
data(iris)
cloud(Sepal.Length~Petal.Length*Petal.Width,data=iris,
groups=Species,screen=list(z=20,x=-70),
2006 Oct 19
2
How to get multiple Correlation Coefficients
Hi
I have used a polycor package for categorical correlation coefficients.
I run the following script. But there were no results.
Could you tell me how to correct the script?
Thanks in advance,
vars <- names(sdi)
for (i in 1:length(vars)) {
for (j in 1:length(vars)) {
paste(vars[i]," and ", vars[j])
polychor(vars[i], vars[j])
# corr
}
}
--
Kum-Hoe Hwang, Ph.D.Phone :
2004 Jan 30
4
Dovecot crashes on certain spam messages
Dovecot crashes. I think it's because of some message in my spam
folder. It has happened once before, and that time I solved it by
deleting that folder. It happens when I start gnus ("Checking messages
in folder spam" or something like that), which makes gnus just stop,
or when I try to enter that folder in mutt.
Jan 30 17:07:09 kalle imap(ke): file imap-bodystructure.c: line
278
2008 Jan 24
1
singular.ok in lm
Dear R users,
I'm wondering about the singular.ok option in lm. If singular.ok is
set to TRUE does it mean that we allow the generalized inverse of
(X'X)^-1 (where X are the independent variables and ' denotes the
transpose)? Or is the singularity handled in some other way?
Thank you!
Best regards,
Martin.
========================================
Martin Eklund
PhD Student
2006 Nov 29
2
Dummies multiplied with other variable
Hi,
I would like to estimate something like y = a + b*d2*y + c*d3*y where
the dummies are created from some vector d with three (actually many
more) levels using factor(). But either there is included the variable
y or d1*y. How could I get rid of these?
Example:
x = c(1,2,3,4,5,6,7,8)
y = c(3,6,2,8,7,6,2,4)
d = c(1,1,1,2,3,2,3,3)
fd = factor(d)
lm(x ~ fd*y)
gives:
Coefficients:
(Intercept)
2006 Sep 15
2
missing data codes
Dear all,
I am new to R. I wish to use R's multiple imputation to deal with missing
data. I have a data set with the size around 300 observations and 150
variables. I checked the help function in R and could not locate how to
write the codes for this. can anyone give a hand?
Do appreciate your time and kindness!
Q.
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2006 Sep 13
2
kendall's w
Hi,
I try to calculate Kendall's W coefficient and I have a bizarre error.
little.app.mat<-matrix(c(1,3,4,2,6,5,2,4,3,1,5,6,3,2,5,1,5,4),nrow=3,byrow=TRUE)
print(kendall.w(little.app.mat[-1,]))
>>> Kendall's W for ordinal data
>>> W = 0.7753623Error in if (is.na(x$p.table)) { : argument is of
length zero
2006 Mar 06
1
Announce of our Xen project; Routing simulation with Einar
Hello all,
Some time before Christmas, a project was started. The task was to
enhance an existing LiveCD solution with User-mode Linux. A number of
requirements was stated, where the greatest challenge was to fit 10
virtual routers within an old no-name PC with only 256MB Ram. And the
solution must still be run from a LiveCD.
Thanks to Xen, the task was possible to complete.
-But, what does it
2006 Sep 20
5
multiple lines and plot
Hi. Please, how can I put together 2 or more lines at the same
scatterplot ? Example: measures of protein intake (quantitative) of 4
children over 30 days, by day. How to plot all children at same graphic:
Protein X Time ? Is there any command like "overlay" ?
Thank you,
Mauricio
2006 Sep 14
1
time varying covariates
Hello,
I am trying to model an intensity function with time-varying covariates.
Before, I have successfully defined a log likelihood function for a
Power-Law Process (lambda(t)=alpha*beta*t^(beta-1)) with two paramters
and no covariates for a repairable systems with failure times (t).
This function was maximized with R optim. No problem!
But now I want to include a covariate indicating a
2006 Sep 20
2
Poission distribution
The expected number of bladder cancer over next 20 years a tire
industry is 1.8. Poission distribution is assumed to hold and 6
reported deaths are caused by bladder cancer among the employees.
Trying to find how unusual this event is.
> ppois(q=6, lambda=1.8, lower.tail = TRUE, log.p = FALSE)
[1] 0.9974306
not sure if ppois is the right one to use and the parameters...
thx much
2006 Oct 24
2
colinearity?
I'm sorry to all those who are tired of seeing my email appear in need of
help. But, I've never coded in any program before, so this has been a
difficult process for me.
Is there a simple function to test for colinearity in R? I'm running a
logistic regression and a linear regression.
Thanks for the help!
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2006 Sep 19
2
bubble plot problems
Hi,
I'm having some problems with a bubble plot (ps package). I don't want
tick marks on all four sides (just two), I want to have a smaller font
size, and I would like to be able to define bubble sizes shown in the
legend (now it shows 0, 0, 0, 9.747 and 4265.757 which is not really
convenient. Passing some of the standard plot arguments didn't help (in
fact, nothing changed).
2007 Jan 20
3
Insert R logo
Dear all R users,
I want to insert the R logo in every graphic that I made in my Statistical
analysis using R. Can anyone tell me whether is it possible or not and if
possible how to do this? your help will be highly appreciated.
Thanks and Regards,
Arun
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2006 Sep 27
3
Converting text to numbers
Hi,
I have Forecast Class and Observed Class in a data matrix as below.
> Sample1
FCT OBS
1 1 5
2 2 4
3 3- 3+
4 3 3
5 3+ 3-
6 4 2
7 5 1
I want to find the difference between Observed and Forecast Classes.
How can I get this done?
I tried to following to convert the 1 through 5 classes, to 1 through 7
for both OBS and FCT column.
> Sample1$OBS2 <- Sample1$OBS
2006 Sep 19
3
Reading a file in R
Dear R helpers,
I am trying to read a CSV file in R called EUROPE (originally an Excel
file which I have saved as a CSV file) using the command
EUROPEDATA <- read.csv("EUROPE.csv")
EUROPE.csv is basically a matrix of dimension 440*44, and has a line of
headers, i.e. each column has a name.
Using read.csv I can't load the data into R properly. Although the first
20 columns or
2006 Dec 05
4
incidence and adjacency matrix conversion
Dear all,
how can I convert an m x n incidence matrix into an m x m adjacency
matrix or an n x n adjacency matrix? The current matrix contains binary
data, hence the new matrix would contain counts of common occurrences.
Thank you for your help.
Phil
2006 Sep 20
4
Calculating mean together with split
Hi
I have a table called npl containing results of simulations.
It contains about 19000 entries and the structure looks like this:
NoPlants sim run year DensPlants
1 6 lng_cs99_renosterbos 1 4 0.00192
.
.
.
it has 43 different entries for sim and year goes from 1 to 100, and run
from 1 to 5.
I would like to calculate the mean of DensPlants for each