AIMMS Language

I currently have a study concerning bi-objective optimization. To give context, the two objectives are to minimize total cost and to minimize the average travel distance. As of the moment, I am only a beginner in using AIMMS and I only know how to use it for single-objective problems. I just want to know if it is possible in AIMMS to do multi-objective optimization? If yes, how can I do it?

I’m currently doing an optimization model through AIMMS and I want to consider multiple scenarios for my study. Is it possible that I have considered, for example, 100 scenarios and my decision variables will only arrive at one solution that considers all scenarios?In my case, I only have one varying parameter (waste generation) in each scenario. I just want to clarify if it is possible in AIMMS and I want to know how it happens that it will arrive only at one solution. It would be a great help if you can answer my query. Thank you!

When I use the "DistributionInverseCumulative" function for beta distribution, I get the following error message from Visual C++:--Assertion failed!Program: ...Aimms\4.85.5.3-x64-VS2017\Bin\libaimms3.dllFile: c:\gitlab-runner\builds\pvap61xc\0\aimms\a...\beta.cppLine: 173Expression: istat==0--In the MainInitialization I implemented the function as follows:b_p_1 := 6;b_q_1 := 3;b_a_1 := 1;b_b_1 := 5;for n doy(n) := DistributionInverseCumulative(Beta(b_p_1,b_q_1,b_a_1,b_b_1), Uniform(0,1))endfor;For other distributions (e.g. normal distribution) the "DistributionInverseCumulative" works without any problems.I would appreciate any pointers on what I should do so that this function doesn't produce an error message?

I am trying to open a project that was originally written in version 4.37. However I have a Community License so the earliest version I can use is 4.77. I have tried opening this project in both 4.77 and 24.2 and both will crash upon opening the project with no error message.I understand the large difference in versions may be causing an issue but I have no way to test on earlier versions. Is there any way I can identify what exactly is causing this issue and could it be something other than a version issue?

Hi! Does anyone know how to interrupt the calculation process and display the current results?

Hi all, I am aware that AIMMS will use all of the indices specified on the Left Hand Side of an assignment statement to loop over all combinations.When trying out something in a test project I am working on, I wanted to use this logic, but found that this does not work anymore when you are using formatstring on the LHS. Was wondering if this is on purpose or whether this behavior should be possible Example that works:spStringParameter( StringToElement(sTargetSet, iSource, 1) ) := formatstring("Test :: element %e", iSource) ;  Example that does not work:spStringParameter( StringToElement(sTargetSet, formatstring("%e", iSource), 1) :=  formatstring("Test :: element %e", iSource) ;  When running the second one, I get an error indicating that the scope of iSource has not been specified. The above is a minimal example of the problem, not completely the same as what I had. I can work around it by either putting the statement in an explicit for-loop, or create the mapping isource → itarget in

dssuc::PR_UserManagement_Intilization(    LP_Set_IsDeveolperDetails_Required : 1 ,     Sp_thisappallowed_for_nonemployee : "Yes" ,     LS_ADGroup_Usageallowed           : {'E.G','C.G'},     LS_ADGroup_Trainingallowed        : {'E','T.G'} ); PR_UserManagement_Intilization is procedure taking 4 arguments and last 2 is sets.  I am trying to pass sets as shown above and shown belowdssuc::PR_UserManagement_Intilization(    LP_Set_IsDeveolperDetails_Required : 1 ,     Sp_thisappallowed_for_nonemployee : "Yes" ,     LS_ADGroup_Usageallowed           : data{'P.G','R.p'},     LS_ADGroup_Trainingallowed        : data {'P.G','R.G'} ); Its showing errorerror for first one is The 'LS_ADGroup_Usageallowed' argument expects a direct reference to an identifier. data is not expectedPlease help me to resolve this issue 

Now and then, at AIMMS user support, we get questions about creating archives and extracting from archives. I briefly summarized some options available here as illustrated below.After executing the four buttons, the contents of sampleFolder are copied to sampleCopyFolder. 

Dear AIMMS Community,Does anyone have any tips/documentation/experience for moving parameters and data to a different CDM category? (or, perhaps alternatively, create a new parameter in the correct category and then migrating the data). As background: for a customer we are using scenario functionality, with each scenario consisting of 3 CDM categories: master data, dynamic data and planning data. Scenarios can share the same version of this data, e.g. 2 scenarios using the same master data but different dynamic & planning data.Currently the customer doesn't use this option of shared data, because a few parameters within the master data category are actually dynamic. So we want to move these parameters (or perhaps solve it in a different way?) Does anyone have experience with moving data to a different category? We already have many scenarios that we want to keep, so anything we do should leave those intact (in theory that should be possible, because currently none of the scenarios

We've published a 'starting point’ for all things related to data integration with AIMMS. It includes a Data Integration Helper that can guide you towards the right solution for your scenario, including a step-by-step guide on how to implement that route. We hope this helps you taking the first steps towards (upgrading your) data integration with AIMMS 🤗. Take a look here!

Introduction:In the ever-evolving realm of mathematical modeling, efficiency and precision stand as central pillars. AIMMS, through its Developer License, unveils a revolutionary asset: the Math Program Inspector. More than a mere addition to the modeling toolkit, it acts as a dynamic catalyst, propelling model development towards greater speed and robustness. In this exploration, we delve into the core of AIMMS Math Program Inspector, unraveling its significance and tangible impact in the real world.Within a landscape where efficiency dictates success, the Math Program Inspector positions AIMMS as a frontrunner among its competitors. Unlike traditional methods of model analysis that often entail laborious scrutiny of extensive text outputs, this tool presents a visual and streamlined approach, empowering developers to comprehend and traverse models with unparalleled ease. Whether the task involves incremental adjustments, pinpointing numerical intricacies, or resolving infeasibilities

Hi All,I’m trying to write a parameter with dex using dex::WriteToFile() procedure. The parameter has an index year that is a subset of the calendar year. (simple calendar with unit year). The excel download won’t fill the year column (see screenshot below). I have the latest .dex library 23.1.1.2).  Could anyone explain what went wrong here?

Hi Community.. Please how can i create a sen and subset with 10 Cities? where the Citie 1 is the Depot? .. 

Dear community,I have a question about min and max values for variables. I have a nonlinear problem. What I want to model is that if the variable a(t) has a value larger than 2,000,000, it should be set to 2,000,000. But it is no problem that a(t) is above 2,000,000, it should not be “punished”. I have the same for the minimum value -400,000. When I just set the min and max values in the range of the variable when I define it, it seems that the optimal solution found is one where the variable a(t) does not exceed 2,000,000 or gets below -400,000.Am I right in my understanding of the range of variables? And how do I then correctly impose these constraints?Thank you in advance :)

Hello AIMMS Community!We're thrilled to extend an invitation to you for our AIMMS project designed for the AIMMS Santa 2023 Challenge. 🚀Overview:Our project provides a straightforward approach to tackle the AIMMS Santa Challenge of 2023. It includes essential data structures and procedures to kickstart your journey. In this initial version, our primary focus is on generating the sample submission file, laying the foundation for further optimizations.Quick Start:To get started, use the `MainExecution` procedure. It's designed to replicate the sample submission, for learning purposes.Data Handling:You'll find parquet files with all the necessary data for individual IDs in the `parquet` folder. Whether you choose to regenerate them or read directly, you'll significantly enhance model performance.Key Procedures and Structures:Explore key procedures like `pr_importAllFiles` and `pr_exportSubmissionFile` to streamline data handling and result exporting.How to Get Started:Clone the repositor

I recently came across this brief comparison by GAMS: https://www.gams.com/blog/2023/07/performance-in-optimization-models-a-comparative-analysis-of-gams-pyomo-gurobipy-and-jump/ Wouldn’t it be very insightful if AIMMS can provide a similar comparison; and, further, mention its advantages over more generic programming languages/packages such as Pyomo, JuMP, GurobiPy? 

Good afternoon!I’m having an issue concerning the use of inline and defined Variables.In order to simplify the code, I’m used to implement expressions in my models using inline variables (Variable > Property > Inline). Currently, I’m in a situation where my model turns out to be “Infeasible or Unbounded” when I try to solve it with an inline Variable, but when I remove the “Inline” property and convert the same Variable in a _defined one, the model is solved with no problems. What could be happening? If a model is feasible when I’m using a defined variable, when I change it to an Inline variable shouldn’t it be feasible as well? Thank you!

Today I got the question to write to Excel numeric data up to a selected precision.Converting to strings didn't work out, as strings will be strings in Excel.The trick I used is to avoid converting to strings, but use the round function, as this function can round up to a certain number of decimals (positive and negative!).

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) In an iterative operator:sum((i,j) | restriction(i,j), term(i,j) ) In the index domain attribute of an identifier: Index domain: (i,j) | restriction(i,j) In a for statement: for (i,j) | restriction(i,j) do    ! some code  endfor; In a constructed set expression: MySet := { i | restriction(i) }! or MyRelation := { (i,j) | r

I have set and values are assigned to set after clicking button on UI. I also want to show what are the values are addi=ed to set on UI. can you please guide what is widget suitable for this purpose. I tried with table. below is screenshot for same. But it is displaying 1 addition to set values.  

SetElementAdd(Li_available_section,LE_add_section,Li_required_section); need add to add elements (Li_required_section-user defined string) to Li_available_section  subset of allsections using element parameter using LE_add_section-subset of allsections.  i am getting below errors.  Domain mismatch in argument 2: the set "LS_required_sections" does not share the same root set as "LS_available_sections" on argument 1.  it will be helpful if you can provide solution

I created procedure with argument(2 input arguments & one output argument) say x.  i called procedure x by passing local arguments(2 inputs & 1 output) from other procedure with arguments.  i am getting below error on output argument of x: The local set local set "LS_available_sections" is passed implicitly and therefore it cannot be modified.

Hi folks! We’re doing a bit of research into “what is it like to learn AIMMS after using Python for modeling”. Curious if anyone has some first hand experience to share about that?A few specific questions:What is easier to do in AIMMS, what is easier in Python? What is the most noticeable difference in the coding itself when creating models in AIMMS vs. Python? Which resources did you find most useful when learning AIMMS, and would you have preferred a specific guide comparing it with coding in Python? Do you combine Python code with AIMMS models?Your comments on any of these are greatly appreciated!

Hi all,We have a relatively simple math program with the potential for duplicate columns. However, knowledge of which variables are duplicates is actually beneficial to the user.While I could go through and examine my parameters/constraints to manually search these, a much faster (computationally speaking) option would just be to have CPLEX report them out to the user, as I wouldn’t need to iterate through lots of parameters. Is there a way I can easily take these warnings from CPLEX and give them to the user? Any help would be appreciated here. Thank you in advance!