similar to: Linear programming with sparse matrix input format?

Hi. I am trying to use the linear optimizer from package lpSolve in R 2.4.1 on Windows XP (Version 5.1). The problem I am trying to solve has 2843 variables (2841 integer, 2 continuous) and 8524 constraints, and I have 2 Gb of memory. After I load the input data into R, I have at most 1.5 Gb of memory available. If I start the lp with significantly less memory available (say 1 Gb), I get

Hi list, I want to find the total maximum resources I can spend given a set allocation proportion and some simple budget constraints. However, I get suboptimal results via lp and friends (i.e. lpSolve and simplex in the linprog and boot) . For example: library(lpSolve) proportions = c( 0.46, 0.28, 0.26) constraints = c( 352, 75, 171) lp(objective.in = proportions, const.mat =

Hi everyone, i?m a new user of R and i?m trying to translate an linear optimization problem from Matlab into r. The matlab code is as follow: options = optimset('Diagnostics','on'); [x fval exitflag] = linprog(f,A,b,Aeq,beq,lb,ub,[],options); exitflag fval x=round(x); Where: f = Linear objective function vector (vector of 45,rows) A = Matrix for linear inequality

Dear all, I am trying to find a solution satisfying the below equations in R. Set up the problem 9 X1+ X2 + X3 = 2 X1+ X2 + X3 = 1 which is subjected to 0 < X1 < X2 < X3 < 2. I have downloaded the packages \'linprog\' and \'lpSolve\' but can not see how to solve the question. Thank you for your help. With

Dear everyone, I don't know much about Integer Programming but am afraid I am facing a problem that can only be solved via Integer Programming. I was wondering if those of you who have experience with it could recommend an R package. I found the following R packages: Rglpk glpk lpSolve lpSolveAPI Are there any others? Are some of them easier to use than others for a beginner? Any advice

Hi. I recently tried the following in R 2.5.1 on Windows XP: >ev2<-c(0.8,-0.6) >ev1<-c(0.6,0.8) >ev1%*%ev2 [,1] [1,] -2.664427e-17 >sum(ev1*ev2) [1] 0 > (I got the same result with R 2.4.1 on a different Windows XP machine.) I expect this issue is very familiar and probably has been discussed in this forum before. Can someone please point me to some

Recently, a package for convex optimization was announced for Python, based upon the LP solver GLPK, the SDP solver in DSDP5, and the LP and QP solvers in MOSEK. I'm aware GLPK is available for R, but wondered if anyone had good packages for convex optimization along these lines for R. TIA.

Hi. I have a procedure that reads a directory, loops through a set of particular .RData files, loading each one, and feeding its object(s) into a function, as follows: cvListFiles<-list.files(fnDir); for(i in grep(paste("^",pfnStub,".*\\.RData$",sep=""),cvListFiles)){ load(paste(fnDir,cvListFiles[i],sep="/")); myFunction(rliObject); rm(rliObject); };

Hi. Suppose I have a vector that I partition into disjoint, contiguous subvectors. For example, let v = c(1,4,2,6,7,5), partition it into three subvectors, v1 = v[1:3], v2 = v[4], v3 = v[5:6]. I want to find the maximum element of each subvector. In this example, max(v1) is 4, max(v2) is 6, max(v3) is 7. If I knew that the successive subvector maxima would never decrease, as in the example,

Hi. If I have a vector, v_1, and another vector of positive integers, i_1, the same length as v_1, then rep(v_1,i_1) will repeat v_i[j] exactly i_1[j] times, like so: >rep(c(1,2,3),c(3,2,1)) [1] 1 1 1 2 2 3 > I'd like to do the same sort of thing where I replace v_1 with a matrix, and the jth row of the matrix is repeated i_1 times. Obviously, I could do this with for loops, like

Hi. I am using R 2.3.1 on WIndows XP, and I am having trouble with the rank function in the presence of numerical NA data. I want the NA's all to get the same rank, but they don't. Here is an example from my session: >ct_align_rets_f2$liq[6851:6859] [1] 115396 NA 362595 NA 242986 340805 NA 692905 251533

Hi. I have the following code in a loop. It splits a vector into subvectors of equal size. But if the size of the original vector is not an exact multiple of the desired subvector size, then the first few subvectors have one more element than the last few. I know that the cut function could be used to determine where to break up the vector, but it doesn't seem to provide control over

Hi. I'm having trouble testing for existence of an object inside a function. Suppose I have a function: f<-function(x){ ... } and I call it with argument y: f(y) I'd like to check inside the function whether argument y exists. Is this possible, or do I have to either check outside the function or pass the name of the argument as a separate argument? If I do exists(x) or

Hi. You folks are so clever, I thought perhaps you could help me make another procedure more efficient. Right now I have the following setup: p is a vector of length m g is a list of length n, g[[i]] is a vector whose elements are indices of p, i.e., integers between 1 and m inclusive); the g[[i]] cover the full set 1:m, but they don't have to constitute an exact partition, theycan

Hi. I'm checking into robust methods for principal components analysis. There seem to be several floating around. I'm currently focusing my attention on a method of Hubert, Rousseeuw, and Vanden Branden (http://wis.kuleuven.be/stat/Papers/robpca.pdf) mainly because I'm familiar with other work by Rousseeuw and Hubert in robust methodologies. Of course, I'd like to obtain

Hi. I am using R 2.5.1 on a Windows XP machine. Here is an example of a piece of code I was running in older versions of R on the same machine. I am looking for underscores and replacing them with periods. This result is from R 2.4.1: >gsub ( "\\_+","\.","AAA_I") [1] "AAA.I" > Here is what I get in R 2.5.1: >gsub (

Hi. There was an interesting thread about a year ago, called 'Command equivalent of rgui "File, Save to File"?' (http://tolstoy.newcastle.edu.au/R/e2/help/06/09/0553.html) started by Michael Prager, and contributed to by Duncan Murdoch (I didn't notice anything beyond the four entries they posted). The question was how to replicate programmatically the "Save to

Hello everybody, I am looking for a function (or package) which can solve a integer optimization problem. I have found the glpk package but I don't known very well how to use it. Someone has another solution ? thx

Hi. It seems that nearly every time I try to use factanal I get the following response: >faa2db1<-factanal(mretdb1,factors=2,method="mle",control=list(nstart=25)) Error in factanal(mretdb1, factors = 2, method = "mle", control = list(nstart = 25)) : unable to optimize from these starting value(s) > In the case cited above, mretdb1 is synthetic data created

Hi. I am using R 2.3.1 on Windows XP. I had installed a library package into my first session and wanted the same package in my second session, so I went out to the CRAN mirror and tried to install the package, and got the following message: ********************************************************************* >utils:::menuInstallPkgs() trying URL