Displaying 20 results from an estimated 4000 matches similar to: "Weighting data when running regressions"
2008 Jun 12
2
numbers as part of long character
Hi,
I'm looking for some way to pick up the numbers which are contained and buried in a long character.
For example,
outtree.new="(((B:1204.25,E:1204.25):7581.11,F:8785.36):8353.85,C:17139.21);"
num.char =
2007 Dec 17
3
Cannot grasp how to apply "by" here...
I have a data frame named "database" with panel data, a little piece
of which looks like this:
Symbol Name Trial Factor1 Factor2
External
1 548140 A 1 -3.87
-0.32 0.01
2 547400 B 1 12.11
-0.68 0.40
3 547173 C 1
2008 Jan 22
1
R: determinants and inverses
hello all
sorry for the following "none" R related question.
does anyone know of a reference to calculate the following identity:
|I + ABC|
where I is an identity matrix and A, B,C may not have to be square matrices?
you help will be greatly appreciated.
H. V. Henderson; S. R. Searle
SIAM Review, Vol. 23, No. 1. (Jan., 1981), pp. 53-60.
provides a result to
2007 Dec 14
4
rcom close Excel problem
Hello,
I just discovered that I cannot close the Excel application and task
manager shows numerous copies of Excel.exe
I tried both
x$Quit() # shown in the rcom archive
and
x$Exit()
and Excel refuses to die.
Thank you very much.
S.
"You can't kill me, I will not die" Mojo Nixon
I also have a problem with saving. It produces a pop-up dialog and
does
not take my second
2007 Dec 22
2
Understanding eval
After many hours of debugging code, I came to the conclusion that I
have a fundamental misunderstanding regarding eval, and hope that
someone here can explain to me, why the following code acts as it does:
foo <- function(expr) {
eval(substitute(expr), envir=list(a=5), enclos=parent.frame())
}
bar <- function(er) {
foo(er)
}
> foo(a)
[1] 5
> bar(a)
Error in eval(expr,
2010 Apr 27
3
Problem calculating multiple regressions on a data frame.
Hi there,
I am stuck trying to solve what should be a fairly easy problem.
I have a data frame that essentially consists of (ID, time as seqMonth,
variable, value) and i want to find the regression coefficient of value vs
time for each combination of ID and Variable.
I have tried several approaches and none of them seems to work as i
expected.
For example, i have tried:
2008 May 02
1
Phil Spector's book
Since we're on the topic of book reviews, I just received Phil Spector's
new R book called "Data Manipulation with R" and it is also quite a
nice book. I haven't gone through it all and I won't give a detailed
review but I have gotten a lot out of the first 100 pages that I have
read.
Note that I've been using R for almost 1.5 years so , for me, it's a
2007 Feb 04
4
Reading expressions from character vectors
Greetings,
I have a problem that I am sure is very straightforward, but I just
can't wrap my head around it. I've read the help pages on text,
plotmath, expression, substitute, but somehow I can't find the answer
to this simple question.
Basically consider the following example:
plot( NULL, xlim = c(0,2), ylim = c(0,2) )
expressions <- expression( -infinity, infinity )
2011 Oct 18
1
cygwing warming when creating a package in windows
Dear All,
I am a beginner creating R packages. I followed the Leisch (2009) tutorial
and the document ?Writing R Extensions? to write an example.
I installed R 2.12.2 (I also tried R2.13.2), the last version of Rtools and
the recommended packages in a PC with Windows 7 Home Premium.
I can run R CMD INSTALL linmod in the command prompt and the R CMD check
linmod. The following outputs are
2013 Mar 12
1
Cook's distance
Dear useRs,
I have some trouble with the calculation of Cook's distance in R.
The formula for Cook's distance can be found for example here:
http://en.wikipedia.org/wiki/Cook%27s_distance
I tried to apply it in R:
> y <- (1:400)^2
> x <- 1:100
> lm(y~x) -> linmod # just for the sake of a simple example
>
2007 Nov 07
3
Indexing, and using an empty string as a name
Hello all,
I ran into the following, to me unexpected, behavior. I have (for
reasons that don't necessarily pertain to the question at hand, hence
I won't go into them) the need/desire to use an empty string for the
name of a vector entry. Perhaps I did not read ?"[" very carefully,
but it seems to me that he following lines should return "1" at the end:
2009 Oct 26
2
What is the most efficient practice to develop an R package?
I am reading Section 5 and 6 of
http://cran.r-project.org/doc/contrib/Leisch-CreatingPackages.pdf
It seems that I have to do the following two steps in order to make an
R package. But when I am testing these package, these two steps will
run many times, which may take a lot of time. So when I still develop
the package, shall I always source('linmod.R') to test it. Once the
code in
2007 Mar 01
2
R code for "Statistical Models in S" ?
I just acquired a copy of "Statistical Models in S", I guess most
commonly known as the "white book", and realized to my dismay that
most of the code is not directly executable in R, and I was wondering
if there was a source discussing the things that are different and
what the new ways of calling things are.
For instance, the first obstacle was the solder.balance data
2008 Mar 05
4
vertex labels in igraph from adjacency matrix
I am getting some unexpected results from some functions of igraph and
it is possible that I am misinterpreting the vertex numbers. Eg., the
max betweenness measure seems to be from a vertex that is not connected
to a single other vertex. Below if my code snippet:
require(igraph)
my.graph <- graph.adjacency(adjmatrix = my.adj.matrix, mode=c("undirected"))
most.between.vert <-
2008 Jun 07
2
Using lm with a matrix?
I'm trying to do a linear regression between the columns of matrices. In
example below I want to regress column 1 of matrix xdat with column1 of ydat
and do a separate regression between the column 2s of each matrix. But the
output I get seems to give correct slopes but incorrect intercepts and
another set of slopes with value NA. How do I do this correctly? I'm after
the slope and
2010 Jun 21
2
How to predict the mean and variance of the dependent variable after regression
Hi, folks,
As seen in the following codes:
x1=rlnorm(10)
x2=rlnorm(10,mean=2)
y=rlnorm(10,mean=10)### Fake dataset
linmod=lm(log(y)~log(x1)+log(x2))
After the regression, I would like to know the mean of y. Since log(y) is
normal and y is lognormal, I need to know the mean and variance of log(y)
first. I tried mean (y) and mean(linmod), but either one is what I want.
Any tips?
Thanks in
2009 Mar 04
3
problems with exporting a chart
Dear R helpers,
I have a problem with exporting a chart (to any format). The graphic device becomes inactive and I get the 'Error: invalid graphics state' error message. I searched the help, web and FAQ but couldn't find the solution.
This is my code:
I chart a histogram for differences in R2 by sample size (an extract from the data is below). Altogether I have n=2500 observations
2007 Jan 14
4
Controlling size of boxplot when it is added in a plot
Greetings,
I am trying to add a boxplot to the bottom of a histogram, right
between the histogram bars and the x axis. Here is the code I am
using at the moment (the par line is probably not relevant for our
discussion):
hs <- hist(x, breaks = 20, plot = F)
par(mar = c(3,3,2,1))
hist(x, breaks = 20, main = NULL, ylim = c(-2, max(hs$counts)))
boxplot(x, horizontal = T, axes = T, add =
2007 Feb 22
1
Cross-tabulations next to each other
I have the following relatively simple problem. Say we have three
factors, and we want to create a cross-tabulation against each of the
other two:
x <- factor(rbinom(5, 1, 1/2))
y <- factor(rbinom(5, 1, 1/2))
z <- factor(rbinom(5, 1, 1/2))
table(x,y)
table(x,z)
This looks like:
y
x 0 1
0 2 0
1 1 2
z
x 0 1
0 1 1
1 2 1
I would like to get (surely this will
2008 May 23
2
About Passing Arguments to Function
Hi,
Below I have a function mlogl_k,
later it's called with "nlm" .
__BEGIN__
vsamples<- c(14.7, 18.8, 14, 15.9, 9.7, 12.8)
mlogl_k <- function( k_func, x_func, theta_func, samp) {
tot_mll <- 0
for (comp in 1:k_func) {
curr_mll <- (- sum(dgamma(samp, shape = x_func,
scale=theta_func, log = TRUE)))
tot_mll <- tot_mll + curr_mll
}