Displaying 20 results from an estimated 1000 matches similar to: "How do I generate multiple (similar) objects within R?"
2006 Jul 04
1
Problems when computing the 1rst derivative of mixtures of densities
Hi everybody,
I am currently working on mixtures of two densities ( f(xi,teta)=
(1-teta)*f1(xi) + teta*f2(xi) ),
particularly on the behavior of the variance for teta=0 (so sample only
comes from the first distribution).
To determine the maximum likelihood estimator I use the Newton-Rapdon
Iteration. But when
computing the first derivative I get a none linear function (with several
asymptotes)
2011 Mar 29
3
Reversing order of vector
Dear R helpers
Suppose I have a vector as
vect1 = as.character(c("ABC", "XYZ", "LMN", "DEF"))
> vect1
[1] "ABC" "XYZ" "LMN" "DEF"
I want to reverse the order of this vector as
vect2 = c("DEF", "LMN", "XYZ", "ABC")
Kindly guide
Regards
Vincy
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2009 Sep 01
3
data frame
HI, R user,
I generate the vectors with the same length. I want to put each vector into each column of data frame. Why it doesnt work`?
rm<-data.frame()
for(a in 1:6){
rm[,a]<-getmeasure(p1,a,speech)
}
thanks a lot
Tammy
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2010 Sep 14
4
Problems with "pdf" device using "plot" "glht" function on "multcomp" library.
Hi R users:
I have de following data frame (called "Sx")
Descripcion Nitratos
Cont85g 72.40
Cont85g 100.50
Cont85g 138.30
Cont80g 178.33
Cont80g 79.01
Cont80g 74.16
Cont75g 23.70
Cont75g 15.80
Cont75g 16.20
Patron80g
2011 Mar 15
2
Matching two vectors
Dear R helpers
Suppose I have a vector as
vect_1 = c("AAA", "AA", "A", "BBB", "BB", "B", "CCC")
vect_1_id = c(1:length(vect_1))
Through some process I obtain
vect_2_id = c(2, 3, 7), then I need a new vector say vect_2 which will give me
vect2 = ("AA", "A", "CCC") i.e. I need the subset of
2008 Mar 13
3
Splitting a set of vectors in a list
I have a set of character vectors of uneven length
that I have stored in a list. I can easily enough get
any column of them using lapply but what I want is to
be able to create a matrix of them. Other than some
kind of brute force looping approach I have drawn a
blank.
Would somebody please suggest something? Thanks
Example.
mylist <- list(aa=c("cat","peach" ),
2009 Nov 24
4
Method
Hello, i would like to ask you another question. Is exist anymethod to
vectors that tells me the last element?That is to say,I have a vector, I
want to return the position of last element. I hope having explained.
A greeting,
Ignacio.
--
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Sent from the R help mailing list archive at Nabble.com.
2018 May 03
4
adding overall constraint in optim()
Hi ?
This is giving me a headache. I?m trying to do a relatively simple optimization ? actually trying to approximate the output from the Excel Solver function but at roughly 1000x the speed. ?
The optimization parameters look like this. The only trouble is that I want to add a constraint that sum(wgt.vect)=1, and I can?t figure out how to do that in optim.
Mo.vect <-
2006 Sep 04
3
Subsetting vectors based on condition
Hello,
I have a question regarding subsetting of vectors. Here's an example of
what I'm trying to do:
vect.1 <- c(76,195, 290, 380)
vect.2 <- c(63, 95, 133, 170, 215, 253, 285, 299, 325, 375)
I would like to subset vect.2 so that it has the same length as vect.1,
and its numbers are the first corresponging higher value compared to
vect.1.
The output should be:
final.output =
2003 Nov 14
7
Vector indices and minus sign
Hi,
I got caught out by this behaviour in 1.8.0 and I wondered why this
happens:
I have a list of vectors and was using lapply and grep to remove
matched elements that occur in only a subset of the elements of the
list:
locs <- lapply(locs, function(x){x[- grep("^x", x)]})
The problem is that where the grep finds no matches and hence returns a
vector of length 0, all the
2007 Nov 14
2
Globalize and acts_as_versioned
The subject says it all: Has anyone had any experience with using
globalize and acts_as_versioned (or equivalent) together. That is, I
would like the version control to take the locales into account, the
en-US translation could be on version 7 while the fr-FR version is 3.
Am thinking about extending these plugins but maybe someone has
already done this?
Tanks in advance.
Regards
Erik Lindblad
2018 May 03
2
adding overall constraint in optim()
Thanks Bert. But everyone on that forum wants to use finance tools rather than general optimization stuff! And I am not optimizing a traditional Markowitz mean-variance problem. Plus, smarter people here. :-)
> On May 3, 2018, at 3:01 PM, Bert Gunter <bgunter.4567 at gmail.com> wrote:
>
> You can't -- at least as I read the docs for ?optim (but I'm pretty
> ignorant
2006 Nov 09
4
Plotting symbols with two positions?
Thanks a lot to Demitris for a prompt answer some minutes ago on another
tread (see below). To avoid excess mails on the list, I move onto next
question:
I have another small plotting problem that confuses me. I want to plot
results from a field trial series, using the numbers of the trials as
symbols in the plot.
pch = as.character(trial_no)
works fine, but truncates the trial number to the
2011 Feb 13
6
From numeric vector to string vector
Hi there, I have a numeric vector let say:
Vect <- c(12.234, 234.5675, 1.5)
Now I want a string vector like:
changedVec <- c("012.234", "234.568", "001.500")
Would be grateful if somebody help me how can I do that.
Thanks and regards,
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2008 Jun 09
1
Cross-validation in R
Folks; I am having a problem with the cv.glm and would appreciate someone
shedding some light here. It seems obvious but I cannot get it. I did read
the manual, but I could not get more insight. This is a database containing
3363 records and I am trying a cross-validation to understand the process.
When using the cv.glm, code below, I get mean of perr1 of 0.2336 and SD of
0.000139. When using a
2012 Dec 11
1
Rprof causing R to crash
I'm trying to use Rprof() to identify bottlenecks and speed up a particullary
slow section of code which reads in a portion of a tif file and compares
each of the values to values of predictors used for model fitting. I've
written up an example that anyone can run. Generally temp would be a
section of a tif read into a data.frame and used later for other processing.
The first portion
2012 Mar 17
3
rtriang using ifelse statement
Hi All,
I want to draw samples (n=4) from one of 2 triangular distributions for
each value in a matrix. I am using an ifelse statement to try to define
which distribution to draw from.
>From the output, I can see that the ifelse statement is choosing the correct
distribution, however, my n=4 simulations aren't occurring. Is there a way
to adjust the ifelse statement to fix this, or must
2018 May 04
0
adding overall constraint in optim()
On Thu, May 3, 2018 at 2:03 PM, Michael Ashton
<m.ashton at enduringinvestments.com> wrote:
> Thanks Bert. But everyone on that forum wants to use finance tools rather than general optimization stuff! And I am not optimizing a traditional Markowitz mean-variance problem. Plus, smarter people here. :-)
>
I'm very confused by these statements. Most of the "finance tools"
2009 Apr 16
2
error bars in matplot
Hi,
I was trying to get error bars in my matplot. I looked at an earlier thread, and the sample code that I made is:
#------------------
library(plotrix)
mat1 <- matrix(sample(1:30,10),nrow=5,ncol=2)
ses <- matrix(sample(1:3,10,replace=T),nrow=5,ncol=2)
vect <- seq(20,100,20)
rownames(mat1) <- rownames(ses) <- vect
colnames(mat1) <- colnames(ses) <- letters[1:2]
2018 May 06
1
adding overall constraint in optim()
Hi Michael,
A few comments
1. To add the constraint sum(wgt.vect=1) you would use the method of
Lagrange multipliers.
What this means is that in addition to the w_i (the components of the
weight variables) you would add an additional variable, call it lambda.
Then you would modify your optim.fun() function to add the term
lambda * (sum(wgt.vect - 1)
2. Are you sure that you have defined