similar to: Vector indices and minus sign

Displaying 20 results from an estimated 20000 matches similar to: "Vector indices and minus sign"

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 =
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
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
2018 May 03
0
adding overall constraint in optim()
You can't -- at least as I read the docs for ?optim (but I'm pretty ignorant about this, so maybe there's a way to tweak it so you can). See here: https://cran.r-project.org/web/views/Optimization.html for other R optimization capabilities. Also, given your credentials, the r-sig-finance list might be a better place for you to post your query. Cheers, Bert Bert Gunter
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
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"
1999 Sep 02
1
count of factors
Hello, I was used to count how many times every factor is found the following way : (assuming 'vect' is a vector of factors) tapply(vect,vect,length) but recently I experienced weird results with this In fact, my command line was tapply(ORGMORE[[1]][vect],ORGMORE[[1]][vect],length) where - 'vect' is a vector of indices - 'ORGMORE[[1]]' is a slightly long vector of
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]
2009 Aug 04
2
can a key of a list be a variable
Hi, I search a solution to record data in dynamic structures in R. I have an algorithm that will be executed each step and whose output is an array of doubles with unknown size. The solution I found is to use lists 1) I initialise my list l <- list() 2) and at a step numbered i I conacatain the new tab to the list vect <- algorithm() l <<--c( l , list(stepi=vect)) The problem is
2007 Aug 10
2
need help to manipulate function and time interval
Hi R-users, I have to define a noise level function L and its energy in the various moment of the day by: if time is between 18:00:00 and 23:59:59 then L[j] <- L[j]+5 and W <- 10^((L+5)/10) if time is between 22:00:00 and 05:59:59 ==> L <- L+10 and W <- 10^((L+10)/10) else L=L and W = W Could someone help me to realize this function please? You will find my following
1999 Nov 30
1
Character2function
If I have several character vectors, for example: a_c('data.') b_c('_myfunction(') c_c('vect.') d_c(')') and, j_1 I can build a vector using paste: x_paste(a,j,b,c,j,d,sep="") x="data.1_myfunction(vect.1)" I have n numeric vectors (vect.1...vect.n) Then, if I could evaluate the string x, I would calculate the result of my function in
2001 Oct 30
2
extracting object names as strings
Hi, I'm looking for a function which returns the name of the argument object as a string: >vect <- 1:3 >function(vect) "vect" I've looked at 'name', 'names', 'objects', none seem to do exactly what I want. ls/objects comes close, but I can't figure out how to force it to give me only one object name. daver
2007 Mar 16
2
MANOVA permutation testing
Hi, I've got a dataset with 7 variables for 8 different species. I'd like to test the null hypothesis of no difference among species for these variables. MANOVA seems like the appropriate test, but since I'm unsure of how well the data fit the assumptions of equal variance/covariance and multivariate normality, I want to use a permutation test. I've been through CRAN looking at
2008 Aug 12
5
produce variable on the fly
Hi guys, I want to create variable on the fly: for example for (i in 1:10) { cat(paste("VAR",i,sep="")) } Will print VAR1, VAR2 etc up to VAR10. However I want to make these into variables, and then give them a value, for example: vect = c(10:20) for (i in 1:10) { cat(paste("VAR",i,sep="")) = vect[i] } THis doesnt work but I hope it demonstrates
2010 Apr 02
1
All sub-summands of a vector
Hello, I'd like to take all possible sub-summands of a vector in the quickest and most efficient way possible. By "sub-summands" I mean for each sub-vector, take its sum. Which is to say: if I had the vector x<-1:4 I'd want the "sum" of x[1], x[2], etc. And then the sum of x[1:2], x[2:3], etc. And then...so on. The result would be: 1 2 3 4 2 5 7 6 9 10 I can
2010 Jul 31
2
vector creation
dear all, consider a simple function like func = function(){ return(runif()) } and say that you would like to create a vector of size N, each entry being a call to this function "func". What is the equivalent of the python code vect = [ func() for i in range(N)] Indeed, you cannot just call vect<-rep( func(), N) - I guess that there also exists a one-liner to do that
2017 Sep 20
0
Updating LLVM Tests for Patch
Hi, I am currently working on a more or less intrusive patch (D37896), which pulls optimizations on multiplications from some back-ends, e.g., (mul x, 2^N + 1) => (add (shl x, N), x) in AArch64, into the DAGCombiner to have this optimization generic on all targets. However, running the LLVM Tests leads to 67 unexpected results. Am 19.09.2017 um 15:58 schrieb Sanjay Patel: > For 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, [[alternative HTML version deleted]]