search for: combinatorial

This is not an R question, but a question on some combinatorial mathematics. Apologies for the OT if it is wildy inappropriate. The traditional C(n.k) method tells me how many combinations k I can make with n objects. However, suppose I want the number of combinations where an object cannot be used more than Q times where Q is a parameter that changes? For ins...

Hi I am looking to perform a discrete mean-variance optimisation, specifically to maximise the ratio of portfolio mean over portfolio standard deviation for a portfolio of several hundred stocks through discrete position size holdings in each stock, where all position sizes must be elements of a small finite set of integer amounts which include zero. I don't think any of the standard R

Hi I am looking to perform a discrete mean-variance optimisation, specifically to maximise the ratio of portfolio mean over portfolio standard deviation for a portfolio of several hundred stocks through discrete position size holdings in each stock, where all position sizes must be elements of a small finite set of integer amounts which include zero. I don't think any of the standard R

Preallocation Instruction Scheduling with Register Pressure Minimization Using a Combinatorial Optimization Approach G. Shobaki, M. Shawabkeh and N. Abu-Rmaileh ACM Transactions on Architecture and Code Optimization (TACO). vol. 10, issue 3, Article 14 (Sept. 2013) http://dx.doi.org/10.1145/2512432 Regards Ghassan Shobaki, PH.D Assistant Professor Department of Computer Science Princess...

Hello! I have the following combinatorial problem. Consider the cumulative sums of all permutations of a given weight vector 'w'. I need to know how often weight in a certain position brings the cumulative sums equal or above the given threshold 'q'. In other words, how often each weight is decisive in raising the cumula...

Hi all I am trying to solve a combinatorial optimization problem. Basically, I can reduce my problem into the next problem: 1.- Given a NxN grid of points, with some values in each cell 2.- Find the combination of K points on the grid such that, the maximum mean value is obtained I took the Travel SalesMan problem example in ?optim docum...

Dear Community, I have a problem I am trying to code in R. Suppose there are 7 products and each have a ROI value attached to it. There are 400 representatives who calls 150,000 customers with these product detailing and achieve sales through the calls. There is a cost per call and revenue earned from the call. Constraint is revenue should be greater than the cost. Now there can be at most 7

Hi all, I'm currently writing some unit tests for some debug line error handling code I'm working on (see e.g. https://reviews.llvm.org/D44382), and I just ran into an annoying disabled feature in gtest, specifically the "Combine" feature for use in combinatorially generating parameterised tests. A FIXME comment in ProfileData\CoverageMappingTest.cpp suggests that I'm not the only one to have tried and discovered that they cannot use this feature. The problem is that the version of googletest (v 1.8.0, released in Aug 2016) in the LLVM tree requires TR1...

I have been struggling trying to write some code to produce all combinations subject to some restrictions. I thought someone might have some bright ideas. I have 11 values which fall into 5 groups. I want all combinations of 2,3, and 4 values where each value must be from a different group. The numbers in the groups are different. Here is a definition of the groups: groups <- list(gp1 =

...ight have some thoughts on this. Could you provide an example here of the motivation for the feature you're missing? Might help motivate the discussion (and/or we'll end up nitpicking how it could be done differently without that feature... - which is sort of where I'm going with this. Combinatorial test case expansion does seem a bit suspicious to me - I'd hope we could pick a few examples from the various equivalence classes & that would suffice?) On Mon, Mar 12, 2018 at 9:01 AM James Henderson via llvm-dev < llvm-dev at lists.llvm.org> wrote: > Hi all, > > I'm c...

...faxed copy I'll gladly provide one. If you have Krebs _Ecological_Methodology_ it's on page 415 of the second edition. It's on page 27 of Gotelli and Graves _Null_Models_in_Ecology_, and in lots of other references as well. The problem is not the calculations of binary coefficients (combinatorials) per se-- I use lgamma(x+1) to do it with logs of factorials-- but rather the 1-(quotient of combinatorials) term in the first summation which forces me to exp() the log terms before the calculation is complete. This invariably causes an overflow (Inf) with all but the most unrealistically small...

...ting to a modern googletest. More modern the better IMO if someone is willing to do the work to make sure it works on all our platforms, etc. However: > Could you provide an example here of the motivation for the feature you're > missing? > I definitely think that the whole space of combinatorial testing should be carefully discussed. Seems like a high risk of long-running tests w/o providing much incremental value. > Might help motivate the discussion (and/or we'll end up nitpicking how it > could be done differently without that feature... - which is sort of where > I'm...

Hi, I have a complex-valued vector X in C^n. Given another complex-valued vector Y in C^n, I want to find a permutation of Y, say, Y*, that minimizes ||X - Y*||, the distance between X and Y*. Note that this problem can be trivially solved for "Real" vectors, since real numbers possess the ordering property. Complex numbers, however, do not possess this property. Hence the

...;3 40 30 40 >4 40 40 40 >5 b 15 NA NA >6 c 20 20 20 >7 d 30 NA NA >8 a NA 10 10 The weird thing about this is (in my view) that each instance of '' is considered unique, so with each successive merge, all combinatorial possibilities are explored, like a SQL outer join (Cartesian product). For non-empty names, an inner join is performed. Dealing with genomic data (10^4 datapoints), it's easy to have a couple of blanks buried in the middle of things, and to combine several replicates with successive merges...

Hello, While reading Dan North''s BDD tutorial <http://dannorth.net/introducing-bdd>, I tried to implement his ATM example as spec stubs. When I first implemented it creating a context for each of his scenarios, I noticed that there is duplication and a combinatorial explosion of the specs. I attached the full files to this email. For brevity, I will use scenario 1 in the body of this email. For the purpose of this exercise, one should imagine that each specification is at least 5 lines. Here is how I implemented scenario 1: context %{A Withdrawal where an A...

Hi R users: In R for windows. is there any package to work, in experimental design? With functions like in S-PLUS , fact.design and the other ones. How to implement in R, all theory about experimental design, I'm talking about ssType3, fact.design and the theory of orthogonal design, combinatory...... Thanks in advance and please excuse me, my "european english". My e-mail is

Hola! I am programming a class (S3) "symarray" for storing the results of functions symmetric in its k arguments. Intended use is for association indices for more than two variables, for instance coresistivity against antibiotics. There is one programming problem I haven't solved, making an inverse of the index function indx() --- se code below. It could for instance return the

...I don't have easy access to other platforms/toolchains etc, so I'd need some assistance for this. > > However: > >> Could you provide an example here of the motivation for the feature >> you're missing? >> > > I definitely think that the whole space of combinatorial testing should be > carefully discussed. Seems like a high risk of long-running tests w/o > providing much incremental value. > These are fair comments, and probably should be judged on a case-by-case basis. In my particular case from https://reviews.llvm.org/D44560, I currently test the...

...on this. > > Could you provide an example here of the motivation for the feature you're > missing? Might help motivate the discussion (and/or we'll end up nitpicking > how it could be done differently without that feature... - which is sort of > where I'm going with this. Combinatorial test case expansion does seem a bit > suspicious to me - I'd hope we could pick a few examples from the various > equivalence classes & that would suffice?) > > On Mon, Mar 12, 2018 at 9:01 AM James Henderson via llvm-dev > <llvm-dev at lists.llvm.org> wrote: >> &...

...sions within the region. I understand that the live range of a live-through register is not affected by the scheduling decisions within the region, but unfortunately, the scheduler that we are integrating in the machine scheduler does need to know the absolute register pressure. Our scheduler is a combinatorial scheduler with an explicit cost function. The explicit cost function is what we call the Peak Excess Register Pressure (PERP), which is basically the number of registers above the physical limit at the highest pressure point in the schedule. If the peak pressure does not exceed the physical limit f...