Hi Tolga, I do not see any problem with: max {a1*x1 + a2*x2 + ... + a800*x800} subject to: x1+x2+ ... + x800 = 100 b1*x1+b2*x2+ ... +b800*x800 <= B c1*x1+c2*x2+ ... +c800*x800 <= C and an additional condition that x1,x2,...,x800 are binary 0-1.
Regards, Moshe Olshansky --- Tolga Uzuner <[EMAIL PROTECTED]> wrote: > Dear R Users, > > I am trying to use LP_SOLVE and would appreciate any > assistance with > the following problem: > - I am trying to choose a fixed number of items out > of a batch of > items: say 100 out of 800 > - items have certain characteristics, say > characteric A, B and C > - I want to maximise the sum of A across all 100 > items I choose while > ensuring that the sum of B and C across the items do > not exceed > certain constraints > > How exactly do I set this up in lp_solve ? If I > associate a boolean, 0 > or 1, with each item, I can constrain the sum of the > boolean to be > equal to 100. But how do I then further specify the > other constraints > (on the sum of B and the sum of C) and the objective > function (to > maximise the sum of A) ? > > Thanks, > Tolga > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, > reproducible code. > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.