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

2024-01-30 Thread Jinsong Zhao
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?

2024-01-30 Thread Martin Becker
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?

2024-01-30 Thread Evan Cooch
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

Re: [R] linear programming

2014-03-17 Thread John P. Burkett
On 03/17/2014 07:57 AM, Barbara Rogo wrote: I have this problem with this form: min (A*X) under some constraints. the unknown is X that is a Matrix. I can't use the function "linp" because in it X is a vector.. How can I do??? Can you help me If X is a matrix, then A*X could be a matrix or

[R] linear programming

2014-03-17 Thread Barbara Rogo
I have this problem with this form: min (A*X) under some constraints. the unknown is X that is a Matrix. I can't use the function "linp" because in it X is a vector.. How can I do??? Can you help me [[alternative HTML version deleted]] __

Re: [R] Linear programming problem, RGPLK - "no feasible solution".

2011-10-13 Thread liuevans
Thank you very much for this! This also solves my original problem. I can't remember at what point I assumed the bounds would be written that way. It was a costly error. Regarding the potential bug, I'm going to report it. R shut down completely every time I ran the program, but didn't when I

Re: [R] Linear programming problem, RGPLK - "no feasible solution".

2011-10-10 Thread Hans W Borchers
Liu Evans, Gareth liverpool.ac.uk> writes: > In my post at https://stat.ethz.ch/pipermail/r-help/2011-October/292019.html > I included an undefined term "ej". The problem code should be as follows. > It seems like a simple linear programming problem, but for some reason my > code is not finding

Re: [R] Linear programming problem, RGPLK - "no feasible solution".

2011-10-10 Thread Liu Evans, Gareth
In my post at https://stat.ethz.ch/pipermail/r-help/2011-October/292019.html I included an undefined term "ej". The problem code should be as follows. It seems like a simple linear programming problem, but for some reason my code is not finding the solution. obj <- c(rep(0,3),1) col1 <-c(1,0

[R] Linear programming problem, RGPLK - "no feasible solution"

2011-10-07 Thread Liu Evans, Gareth
Dear All, RGLPK says that there is no feasible solution but I think there should be. In a more general setup with more variables, where we know the feasible solution analytically, it also says there is no feasible solution. I have tried different values. except the 0s and 1s must stay as they

Re: [R] Linear Programming.

2008-05-27 Thread Arne Henningsen
Hi Marcus! On Wednesday 28 May 2008 05:56, Marcus Vinicius wrote: > Dear all, > May anyone explain to me how I run a linear programming or Data > Envelopment Analysis (DEA models) into R? Package "DEA" (on CRAN): http://cran.r-project.org/web/packages/DEA/index.html Package "FEAR" (NOT on CRAN

Re: [R] Linear Programming.

2008-05-27 Thread Prof Brian Ripley
On my system help.search("linear program") gives (slightly edited) linp(limSolve) Linear Programming solveLP(linprog)solve Linear Programming / Optimization problems lp.object(lpSolve) LP (linear programming) object lpcdd(rcdd) linear

[R] Linear Programming.

2008-05-27 Thread Marcus Vinicius
Dear all, May anyone explain to me how I run a linear programming or Data Envelopment Analysis (DEA models) into R? Thanks a lot. Best Regards. Marcus Vinicius [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://s