Hi Calum, Does this include an error tolerance for the match between the ordered and delivered quantities? That is, is it okay to have a maximum of one unit difference or do deliveries have to exactly match orders?
Jim On Sun, Dec 27, 2015 at 10:08 PM, Polwart Calum (COUNTY DURHAM AND DARLINGTON NHS FOUNDATION TRUST) <calum.polw...@nhs.net> wrote: > I am currently working on a project that is producing Gigabyte sized > vectors that kill R. It can take 24 hours to run. So frustrating to get > that far and have to scale back my inputs and rerun... > > > The problem i'm trying to solve as i see it is very similar to optimal > currency denominations problems combined with a knapsack problem. Let me > TRY to explain. > > > We have a product that we want to manufacture in as few sizes as > possible. like currency if you want 30cents but a 30cent coin doesnt exist > you can join multiple products together. (3x10 cent, 25cent +5 cent, etc) > > > Unlike currency we dont need every value to be possible, we have a list of > known values which are effectively related to each other by the next size > up being 25% bigger. So for instance 64, 80 100. > > > We have some rules that say you can't use more than X products combined to > make the final size. A bit like saying never give more than 10 coins as > change, so you cant issue 20x5cents for a dollar of change. > > > All of that fits a standard currency denomination challenge. > > > We dont need the combinations to be calculated using greedy method. [We > will calculate and store as a table] > > > BUT - we do have a manufacturing limitation that means can manufacture to > any whole number size, we cant do smaller than size5. (We dont go as low as > that anyway... size 11 is as low as needed). So different from any > currency problem I've seen where the lowest coin size is always a 1 > allowing any size to be produced. > > > So i have three questions I'm trying to answer: > > > - what is the smallest product range we can make that achieves our rules > for max combinations of sizes? > > > - Is there a more optimal range. Say the smallest range was 4 sizes, for > example 5,6,23,40. Its possible adding a 22 and a 46 to that may actually > be cheaper than supplying 2x5 and 2x6 or 2x23... > > Currently I'm identifying every possible combination into a matrix. We > have a manufacturing constraint of max size 49 as well. So i take every > end user size possible (from 11 thru to 125). For each size i then take > every combination of possible sizes from 5 to 49 (45 sizes) that we COULD > make and work out how i can achieve all the possible end user sizes, > discarding any combinations that break our rules for max combinations. > > Thats a giant set of for loops. Once i establish the options we can > apply the manufacturing costs and usage data to find the answer. > > For now 45 sizes,combined in any of up to 5 different combinations to do > 10 end user sizes is creating vectors too big for R to handle... > > Long explanation of the problem, to basically say... has anyone come > across a function in R that might simplify this? > > > > Sent from TypeMail<http://www.typeapp.com/r> > > > On 27 Dec 2015, at 08:00, "Polwart Calum (COUNTY DURHAM AND DARLINGTON NHS > FOUNDATION TRUST)" <calum.polw...@nhs.net<mailto:calum.polw...@nhs.net>> > wrote: > > > ******************************************************************************************************************** > > This message may contain confidential information. If you are not the > intended recipient please inform the > sender that you have received the message in error before deleting it. > Please do not disclose, copy or distribute information in this e-mail or > take any action in reliance on its contents: > to do so is strictly prohibited and may be unlawful. > > Thank you for your co-operation. > > NHSmail is the secure email and directory service available for all NHS > staff in England and Scotland > NHSmail is approved for exchanging patient data and other sensitive > information with NHSmail and GSi recipients > NHSmail provides an email address for your career in the NHS and can be > accessed anywhere > > > ******************************************************************************************************************** > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
