Re: [R] linear programming in R | limits to what it can do, or my mistake?

On 2024/1/30 20:00, Martin Becker wrote: Apart from the fact that the statement "such that t1+t2+t3+t4=2970 (as it must)" is not correct, the LP can be implemented as follows: I was confused by "such that t1+t2+t3+t4=2970 (as it must)", otherwise, I also get the same solution. library(lpSol

Re: [R] linear programming in R | limits to what it can do, or my mistake?

Apart from the fact that the statement "such that t1+t2+t3+t4=2970 (as it must)" is not correct, the LP can be implemented as follows: library(lpSolve) LHS <- rbind( c(0,0,0,0, 1, 0, 0,0), c(1,0,0,0,-1, 1, 0,0), c(0,1,0,0, 0,-1, 1,0), c(0,0,1,0, 0, 0,-1,1), cbind(-diag(4),diag(4)), c(0,0,0,0,0,1

[R] linear programming in R | limits to what it can do, or my mistake?

Question for 'experts' in LP using R (using the lpSolve package, say) -- which does not apply to me for the sort of problem I describe below. I've run any number of LP's using lpSolve in R, but all of them to date have objective and constraint functions that both contain the same variables. This

[R] Limits of detection with package pls

I'm using package pls to perform partial least squares regression. Data is four spectra (13178 intensity measurements each) that correspond to 4 concentrations. out <- plsr(concentration ~ intensity, ncomp=2, data=libs, validation = "LOO") Does the package have a command to calculate limits of d

Re: [R] limits on liniar model

It is hard to prove a negative, but to the best of my knowledge lm will not do what you want. This does not mean there is not a function that will perform your analyses; the sort of thing you want to do is often accomplished using non-linear methods. John >>> ראובן אברמוביץ 8/3/2011 12:00:04 P

Re: [R] limits on liniar model

Please use R's search capabilities before posting. RSiteSearch("Linear Model with Constraints") appears to give you what you're looking for. Incidentally, with constraints, the model is no longer linear, I believe. -- Bert 2011/8/3 ראובן אברמוביץ : > >   Can I put limits on the lm() command? I

[R] limits on liniar model

Can I put limits on the lm() command? I only know that you can choose a liniar model with or without an intercept, but can I put other limits on the coefficients (for example- the intercept must be bigger than 1) ? _

Re: [R] limits of a data frame size for reading into R

I sometimes have to work with vectors/matrices with > 2^31 - 1 elements. I have found the bigmemory package to be of great help. My lab is also going to learn sqldf package for getting bits of big data into/out of R. Learning both of those packages should help you work with large datasets in R. Th

Re: [R] limits of a data frame size for reading into R

On 03/08/2010 2:28 PM, Dimitri Liakhovitski wrote: And once one above the limit that Jim indicated - is there anything one can do? Yes, there are several packages for handling datasets that are too big to fit in memory: biglm, ff, etc. You need to change your code to work with them, so i

Re: [R] limits of a data frame size for reading into R

And once one above the limit that Jim indicated - is there anything one can do? Thank you! Dimitri On Tue, Aug 3, 2010 at 2:12 PM, Dimitri Liakhovitski wrote: > Thanks a lot, it's very helpful! > Dimitri > > On Tue, Aug 3, 2010 at 1:53 PM, Duncan Murdoch > wrote: >> On 03/08/2010 1:10 PM, Dimi

Re: [R] limits of a data frame size for reading into R

Thanks a lot, it's very helpful! Dimitri On Tue, Aug 3, 2010 at 1:53 PM, Duncan Murdoch wrote: > On 03/08/2010 1:10 PM, Dimitri Liakhovitski wrote: >> >> I understand the question I am about to ask is rather vague and >> depends on the task and my PC memory. However, I'll give it a try: >> >> Let

Re: [R] limits of a data frame size for reading into R

On 03/08/2010 1:10 PM, Dimitri Liakhovitski wrote: I understand the question I am about to ask is rather vague and depends on the task and my PC memory. However, I'll give it a try: Let's assume the goal is just to read in the data frame into R and then do some simple analyses with it (e.g., mul

Re: [R] limits of a data frame size for reading into R

You probably don't want an object that is larger than about 25% of the physical memory so that copies can be made during some processing. If you are running on a 32-bit system which will limit you to at most 3GB of memory, then your largest object should not be greater than 800MB. If you want to h

[R] limits of a data frame size for reading into R

I understand the question I am about to ask is rather vague and depends on the task and my PC memory. However, I'll give it a try: Let's assume the goal is just to read in the data frame into R and then do some simple analyses with it (e.g., multiple regression of some variables onto some - just a

[R] spatstat: changing r limits when plot envelope

Dear all, I need to change the default of "r" when plotting the output of the envelope function of spatstat package. I can do this manually for the Lest output: ## Example from spatstat Kest help data(cells) L <- Lest(cells, correction="isotropic", r=seq(from=0,to=0.5, by=0.05)) x11(1000,400)

Re: [R] limits

Try the rSymPy or Ryacas packages. In the rSymPy code below the var command defines x as symbolic to sympy and then we perform the computation: > library(rSymPy) Loading required package: rJava > sympy("var('x')") [1] "x" > sympy("limit(x*x + x + 2, x, 2)") [1] "8" Or using devel version define

Re: [R] limits

Uwe Ligges wrote: > So you want some software that can do symbolic calculations? In that > case use other software. R is designed for numerical analyses. In particular, if you are looking for good free software, you might try Maxima. -- Mike Prager, NOAA, Beaufort, NC * Opinions expressed ar

Re: [R] limits

Hassan Mohamed wrote: Hey, what is the R function for the mathematical limit ? e.g. to calculate and return the amount that the expression X^2 +X +2 approach as X approach 2 (X-> 2) So you want some software that can do symbolic calculations? In that case use other software. R is designe

Re: [R] limits

Dear Hassam, Take a look at the section 5.8 in [1]. HTH, Jorge [1] http://cran.r-project.org/web/packages/Ryacas/vignettes/Ryacas.pdf On Tue, May 5, 2009 at 5:39 AM, Hassan Mohamed wrote: > Hey, > what is the R function for the mathematical limit ? > e.g. to calculate and return the amount t

[R] limits

Hey, what is the R function for the mathematical limit ? e.g. to calculate and return the amount that the expression X^2 +X +2 approach as X approach 2 (X-> 2) thanks hassan [[alternative HTML version deleted]] __ R-help@r-project.org

[R] limits/thresholds for arrayWeights in the limma package

Is there any limit ratio of between-array weight values, which one can get using the arrayWeights() function in the limma package ? For instance, if one array has the weight value - let's say - 4 and the rest between 0.5 and 2, shall I

Re: [R] limits on the length of the name of a script file in R 2.6.0.?

On 11/26/2007 11:03 AM, Dimitri Liakhovitski wrote: > Hello! > I posted earlier - about my problems with R 2.6 crashing (i.e., > telling me it needs to shut down) every time I tried to open an R > script. First, it looked like it was unhappy with my working outside > of R folder (under Program File

[R] limits on the length of the name of a script file in R 2.6.0.?

Hello! I posted earlier - about my problems with R 2.6 crashing (i.e., telling me it needs to shut down) every time I tried to open an R script. First, it looked like it was unhappy with my working outside of R folder (under Program Files). But not it looks like it was not really the problem. Now,