AIMMS Language

Hello everyone,I am trying to implement a supply and demand model in AIMMS. This is the first time using it for me and I'm having some issues. The case is as follows: There are Printer companies that supply books to Retailers. These Printers can send the books directly to retailers, or through crossdocks to be consolidated. I have modelled the set of Printers with index P, the set of Crossdocks with index C and the set of retailers with index R. The case asks for a set of locations as the union of these three sets L = P ∪  C ∪ R. I am not sure how to model this union of sets and can't seem to find any info on this. Does anyone know how to do this?Not sure if it matters, but the amount of Printers, Crossdocks and Retailers should be variable and dependent on an Excel input file. Thanks!

Is there an extension or language config so I can view my AIMMS Text Representation with syntax highlighting in VS Code? It would be super helpful. I think I can create one, but if someone's already invented that wheel, no sense in re-inventing it. Thanks, y'all! ~Bon

Dear all, I want to write a code in the MainExecution section. I want to consider in the first cycle a constraint, but I wan't to consider this constraint in the second cycle. How can I write this? Thanks Best GL

Good morning and a very good day to you!Dear Sir / Madam,Currently, I am running big data using AIMMS for my Final Year Project to produce an optimal exam timetable. My MIP model consists of 1 decision variable, 3 objective functions and 14 constraints.I encountered the same problem for many times when I was running my data. I realized that AIMMS will usually shut down on its own after running for more than 2 hours before even getting the results. I have checked my computer to see if it has any technical problems but I have not found any. Can you please help me with this problem? 

Dear all, I must to set the non anticipativity constraints in aimms for the stochastic problem.Then for s scenarios and x decision variable I must to write thatx1=x2=x3=..xsHow can I write this in aimms?Thanks 

Hi, I was trying to play around with Monte Carlo simulation in AIMMS. I can save the results from MP.Objective for every run. But, how can I save the solution for every run? I tried to use something like below for every run:Variable_Result(run, param1, param2) := Variable(param1,param2);It’s in the procedure “RunMonteCarlo” in the attached file. But, it doesn’t work. Any idea?Thanks,Zulfan

Good morning.I am converting our proyects in AIMMS from version 3 to version 4 and the DSN that already was used to connect to Access has failed. I used the extension (*.mdb), also tried with  (*.accdb) but doesn´t work. Could you help?Thanks a lot

Dear,I have a binary variable in my model X(i,j,k,s) and I want that it assumes a value that I calculated in the deterministic model. For example I want that X(i,j,k,s)=X('Yorkshire and the Humber','MEA',k,s);How can I write this in aimms?I tried to write a constraint but after the run of the programme I don't have results for this variable.Thanks for your help. 

Dear community, When I try to solve the attached model, I get the following errors: Warning: The columns "TransportToCustomer(Warehouse1,Customer5,038.001,1)" and "TransportToCustomer(Warehouse1,Customer399,038.001,1)" are equal in the generated mathematical program "LeastCostPlan". This may lead to non-unique solutions. For more information regarding potential causes and consequences, see the help associated with the option "Warning_duplicate_column". Warning: Only 3 out of 11565909 duplicate column warnings were reported. See also option limit_reported_duplicate_column_row_warnings. Warning: After zero iterations CPLEX 12.7.1 concluded that an integer solution to LeastCostPlan does not exist. Firstly, I don't really what this error means. In the example above, the shipping of product 038.001 to Customer5 on Period 1 and the shipping of product 038.001 to customer 399 on Period 1 do not have anything to do with each othe

Beginning on 4.97 AIMMS version, warning and possibly errors will reinforce the differences between the pipe sign (|) and the dollar sign ($). A new article discusses deeply the historical reasons and the differences, but you can also have a peak of the differences below.  Dollar SignThe $ is used to impose a condition on a part of an expression as in:A(i) := B(i) $ C(i);This is semantically the same as:A(i) := if C(i) then B(i) else 0 endif;Pipe SignThe operator | is used to restrict an index domain. An index domain can be specified at several places in the model: At the left-hand-side of a multi-dimensional assignment:A((i,j) | restriction(i,j)) := rhs(i,j)

Dear all, I want to create a cycle for-do and I want to have the values of the results for each considered point. How can I write this in aimms? For now I wrote this for e| (epsilon_e(e))>epsilonl and (epsilon_e(e)) CO2_ec:=epsilon_e(e); solve Min_Total_Costs; Total_Costs_e(e):=Total_Costs; endfor; with e the index of a set epsilon_e, while Total_Costs_e(e) a variable. I want to know the value of Total_Costs_e for each e. What is missing in the code? Thanks Best GL

Hi All,I hope you are doing well! I have a question:I am programming a model with 3 objective functions. The goal is to find the best locations for production.I have diffrect sources, one destination and 4 products.All the objective functions are linear and I used GMP::Column::SetAsMultiObjective to solve them similar. The first function minimizes the costs (price * X(decision variable) + transportation cost * X)The second one minimizes the produced CO2 (CO2 in production * X + CO2 during transport * X)In the last one I want to maximize the social benefit, therefore I wanted to use a binary variable, so if X at a source location is > 0 the binary Variable Y should be 1 (0 otherwise).so the objctive function should be: (Number of created Jobs + other social aspects) * Y This is what I got so far:

Dear staff,I would like to receive some help writing the following constraint for a mathematical model.Within a graph, I define arcs (i-j) where “i” and “j” are nodes. For each arc and node, I also have the following variables and parameters:p(i) binary variablep(j) binary variablea(i,j) continuous variableC(i,j) parameterH(i) parameterH(j) parameterI would like to write a constraint expressing the following conditions:if p(i) = 1 and p(j) = 0, then a(i,j) <= C(i,j)*H(j)if p(i) = 0 and p(j) = 1, then a(i,j) <= C(i,j)*H(i)if p(i) = 0 and p(j) = 0, then  a(i,j) <= C(i,j) * (H(i) + H(j))/2if p(i) = 1 and p(j) = 1, then a(i,j) <= C(i,j)If you have any suggestions on how to write the above conditions within a constraint, I will be glad.Thank you,

Dear All, I want to model a variable that only can be applied for certaint set index. For example: Variable NPGMax {     IndexDomain: (i,g,ng)|ord(i) = 1 or ord(i) = 3 or ord(i) = 6; } where the variable NPGMax is only applied for index 1, 3, or 6 of set bus with index i. Is it possibel to do it dynamiclly where the value 1,3, or 6 can be assigned as an input parameter? Thank you very much.

Dear All, In many publications related to power system expansion planning, model validation is done by applying the developed model to a small system such as Garver 6 Bus and describing the result without detailed explanation to justify the model is valid or not. Is there any specific methods to validate the optimization model? Thank you very much.  

Hi, everyone! I’m trying to import a parameter based on a excel sheet. The cell is empty and the parameter is set with a default value of inf, but the parameter keep assuming value of zero. There’s anything that I can do to, if the cell is empty, the value assumed be different than zero?I don’t know if this should happen or if it’s an issue that has already been fixed. I’m using the verison 4.85, by the way. Thank you very much!

Hello Aimms Community, I have to do a calculation with Parameter K_T(s,i,ii,t) in R and get the calculation results back to Aimms for the Optimization. I want to have the root of the matrix. i and ii are Indices for the same SetIdentifier Sn. code:dl::DataTables+={'MyDataFrame'};empty DataMap;DataMap(dl::dt,dl::idn,dl::cn,dl::dn) += data { !( table_name , identifier , col , dom ) : name_in_dataframe ( MyDataFrame , Sn , 2 , 1 ) : "i", ( MyDataFrame , Sn , 3 , 2 ) : "ii", ( MyDataFrame , P , 4 , 3 ) : "t", ( MyDataFrame , OL , 5 , 4 ) : "s" , ( MyDataFrame , K_T , 1 , 0 ) : "K" } ;MapName:="MyMapName";dl::RemoveDataSourceMapping(MapName);dl::AddDataSourceMapping( MapName, DataMap, dl::DependEmpty,dl::TableAttributesEmpty,dl::ColAttributeEmpty);dl::ExecScript("source('test_rlink.r')",Ma

Hi all, tried to declare a new set with index d. Aimms complained that index d was already used BUT it is not used anywhere in aimms. I just can’t find any sets with index d. Tried also index s; same complaint from aimms. I opened another similar project and I was able to create sets with indices d and a. Not sure what’s happening. Any suggestions would be appreciated    thanks   nick  

When AIMMS is solving on my machine, it consistently uses a little over 21% of the total CPU capacity. Is it possible to let AIMMS use more than this?EDIT: After investigating a little more, the ‘problem’ occurs while AIMMS is building the model. CPU usage during the solve is harder to observe since it is quite quick. The CPLEX 20.1.sta file shows that it prepares to use up to 8 threads.

Dear all, how can I do the stochastic optimization in aimms?Best 

I’m trying something like this, but compound sets does not exists anymore. Someone could please help me?    

Hi Community, I have been looking into the AIMMS error handling feature. During this, the function errh::Category got my attention. This function has an element parameter with range errh::AllPendingErrors as input, and it returns the error category in the range of the predefined set errh::AllErrorCategories. The set errh::AllErrorCategories contains these possible categories: Engine, Internal, Authorization, Licensing, Memory, Limit, Compiler, Syntax, Semantics, Legacy, Execution, Math, InvalidArgument, Unit, IO, External, Generation, MathematicalProgramming, NonlinearEvaluation, Solver, GUI and User. Some examples of how AIMMS classifies errors using the categories are these: When assigning a value of 2 to an identifier with a Binary range, the category is Semantics Doing a division by zero resulted in a Math error What I want is to use these categories in order to control the errors that AIMMS displays by defa

Hello, trying to solve my Thesis Model there has been message about infeasible solution. ''Warning: After zero iterations CPLEX 12.8 concluded that an integer solution to MeanCostPlan4 does not exist.'' the model is about my thesis, so i would appreciate some help. i attach a zipped file(Fdata1 is the data file i use) & the excell for the extra data for Section4. More details about the Model: The problem is in section4. when i run the Mp of section3 i find a solution, but with the data of Section4, infeasibility We use a network of 10Nodes. starting node=i & end node=j. We want to have 2 hubs one from S=Pre-istalled nodes(1-7) & one from T=install new Hub(8-10) we want the whole flow to pass throught the Hubs S&T so i create the variable Z(i,j,s,t) In section1 is the main model, in section2 The installation cost, in section3 constraints about the capacity of the nodes and in Section4 Constraints about

 Hi, Our model exists of 7 optimizations. However, after the 6th optimization it says that it is terminated by the solver, and it ended up in intermediate non-optimal. What does this mean? Did it end up in a local minimum? Or does it mean something else. Can the results be trusted? If not, how can I solve this? Thanks in advance! 

Hello, i am new to aimms and completed the beginners tutorial and tried to understand the machine planning example, but it was to complicated for me to understand all of it. I want to solve a scheduling problem but i have problems creating the model. Let me explain my situation: In the production there are build articles from different orders and they are transported inside the company within containers. The transport limitation is 8 containers an hour. I want to solve the problem and want the best order which is <= 8 containers an hour, if not possible, than the next following orders should be so small, that it will be compensated, if not possible, a gap with no production time should be inserted. It would be ideal, that the same article is produced in one step (e.g. Article 52107 has to be build for 3 different customer orders). After all, i want to visualize it. My first problem is, that i don’t know how to produce on order after another and make the timeline to