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Nonlinear objective with integer decision variables Description The examples describe problems with a nonlinear objective function and some integer
decision variables.
- A craftsman wants to optimise its revenue based on the size of the produced wooden boxes (boxes02.mos)
- Dealers sell apples at a market at the same price and the game is to find the quantity sold and the associated price (pricechange.mos).
Source Files By clicking on a file name, a preview is opened at the bottom of this page.
boxes02.mos (!********************************************************************* Mosel NL examples ================= file boxes02.mos ```````````````` A craftsman makes small wooden boxes for sale. He has four different shapes or styles of box, and can make each of them in any size (keeping all the dimensions in proportion). The profit he makes on a box depends on the size. He has only a limited amount of the necessary wood available and a limited amount of time in the week to do the work. How many boxes should he make, and what size should they be, in order to maximize his profit? (c) 2013 Fair Issac Corporation author: S. Heipcke, Nov. 2005, rev. Feb. 2013 *********************************************************************!) model "Boxes" uses "mmxnlp" declarations BOXES = {"Cube", "Oblong", "Flat", "Economy"} ! Box types make: array(BOXES) of mpvar ! Number produced per box type size, battens, ply, profit, mtime: array(BOXES) of mpvar ! Properties per box type LENGTH,WIDTH,HEIGHT,PROFIT,DUR: array(BOXES) of real ! Length, width, height, profit, time TotalProfit: nlctr ! Objective: total profit end-declarations LENGTH :: (["Cube", "Oblong", "Flat", "Economy"])[1,1,4,1] WIDTH :: (["Cube", "Oblong", "Flat", "Economy"])[1,2,4,2] HEIGHT :: (["Cube", "Oblong", "Flat", "Economy"])[1,1,1,1] PROFIT :: (["Cube", "Oblong", "Flat", "Economy"])[20,27.3,90,10] ![20,24,90,10] DUR :: (["Cube", "Oblong", "Flat", "Economy"])[1,1,1,0.2] forall (b in BOXES) do battens(b) = 4*(LENGTH(b)+WIDTH(b)+HEIGHT(b))*size(b) ply(b) = 2*(LENGTH(b)*WIDTH(b)+WIDTH(b)*HEIGHT(b)+HEIGHT(b)*LENGTH(b))*size(b)^2 profit(b) = PROFIT(b)*size(b)^1.5 mtime(b) = 1 + DUR(b)*1.5^(ply(b)/10) end-do ! Bounds on size and number of boxes forall(b in BOXES) do size(b) <= 2 make(b) <= 6 make(b) is_integer end-do ! Limits on resource availability sum(b in BOXES) make(b)*battens(b) <= 200 sum(b in BOXES) make(b)*ply(b) <= 210 sum(b in BOXES) make(b)*mtime(b) <= 35 ! Objective function: total profit TotalProfit := sum(B in BOXES) make(B)*profit(B) setparam("xnlp_verbose", true) setparam("xprs_nlpsolver", 1); ! Solve the problem maximize(TotalProfit) ! Solution display forall (b in BOXES | make(b).sol>0) writeln(getsol(make(b)), " '", b, "' boxes of size ", getsol(size(b)), " each using ", getsol(battens(b)), " cm of battens, ", getsol(ply(b))," sq cm of plywood, ", strfmt(getsol(mtime(b)),0,2), " hours") writeln("\nTotal profit ", getobjval) writeln("Total battens ", strfmt(getsol(sum(b in BOXES) make(b)*battens(b)),0,2)," cm") writeln("Total ply ", strfmt(getsol(sum(b in BOXES) make(b)*ply(b)),0,2)," sq cm") writeln("Total mtime ", strfmt(getsol(sum(b in BOXES) make(b)*mtime(b)),0,2)," hours") end-model | |||||||||||||||

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