Optimization Tooling

Hello Team, I am working on the multidepot-VRP problem an extension of your practical example capacitated VRP. I want to make a model in which vehicles will depart from their depots to serve different customers and turn back to the same depot where it started from. I made a rough model but facing some sort of errors. Kindly check and help me to resolve my model. I shall be really thankful to you. Looking forward for your kind response. Regards

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

Hi,I am solving a huge MIP (4446310 integer variables). I set the relative gap to 0% from CPLEX MIP settings. After 69532.16 sec (19.3 hours), the model stops running and the solver status says 'Terminated by solver' while the gap is 0.14%. Why does this happen? What are the possible causes? Thank you. Best regards,Wanie Saidi 

Hi, In the Options Tree, I have been changing the MIP Relative Optimality Tolerance to 0.5%, 1.0%, 5.0% and 10.0% to analyse the performance of the solution, gap and solving time. I wish to change the gap to 0.5%, 1.0%, 5.0% and 10.0% to analyse whether the solving time can be reduce by changing the gap. However, the CPLEX always stop at either 0.04%, 0.12% or 0.00% of gap. Is there any way to stop the CPLEX at 10% of gap?

Hi AIMMSians, I am using the AMD 3995WX processor which has 128 logical processors. I realized that a single instance of AIMMS only uses 64 logical processors as processors are grouped by windows’ limit (64 cores). To use all 128 processors, I can run two instances of AIMMS at the same time. The first instance gets affinity of group0. Then I need to modify the affinity of the second instance to use the second NUMA (group1). Still, I would like one instance of AIMMS employs all logical processors. I assume the same problem exists on servers where the number of logical cores often exceeds 64. Is there any way to bypass windows' processor group policy (i.e. make AIMMS group aware) and distribute the job between all 128 available threads? Note 1: I tried CPLEX and GUROBI solvers. I am not sure if this limitation is related to AIMMS or the solvers.Note 2: I am aware of disabling Hyperthreading/SMT, but that is not desirable. 

Hello - I'm creating a script to export a bunch of vars/params to Excel/CSV. It needs be pretty clean/standardized so it can be read into a UI.I tried:write AllVariables to file export_file;But the output was too messy.  - Is there a way to silence Basic/NonBasic? - My output is often Nodes x Time, which AIMMS seems to prefer as (n,t), but then it shows Time as columns instead of rows (which is SUPER ugly in the text file). So I have to duplicate everything as parameters with (t,n) for the export. Or am I wrong? So now I'm looking at using AXLL, but it's pretty tedious.This is what I'm currently doing:axll::CreateSheet("VarName1");axll::WriteTable(Var1, "A2:A5", "B1:AZ1", "", 1, 1);axll::CreateSheet("VarName2");axll::WriteTable(Var2, "A2:A5", "B1:AZ1", "", 1, 1);… ad nauseam There has to be a better way. Is there something

Hi everyone,I have been trying to call an AIMMS (academic license) procedure from python although this doesn't seem to work. I got the following code from another thread, which seems to work with a paid license. I also saw on another post that the academic licence might have some limitations in this regard. Is there an API in another language, were I can make Python wrapper around this other language?orIs it possible that AIMMS internally allows to run scripts in some language, in which case a script can be built  in such a way that they exchange model parameters/inputs/results with the outside world? Best regards,

Hi, I would like to do a multiple optimization in AIMMS. For example I would concurrently minimize the costs and maximize the amount of captured carbon dioxide. How can I set this kind of optimization in AIMMS? Thanks. Best

In converting WinUI to WebUI, I have to convert the popups. Seemingly no problem, right?It is a bit annoying, but fairly easy to do. Here’s the conversion...Old (WinUI) way:pr_DoStuffsp_Answer := DialogAsk(“Here’s a question”, “Yes”, “No”);if sp_Answer = “Yes” then do this elseif sp_Answer = “No” then do that endif; New (WebUI) way (with TWO procedures):pr_DoStuffwinui::RequestPerformDialogWebUI(“”, “Here’s a question”, s_ButtonActions_YesNo, ‘pr_DoNextStuff’); pr_DoNextStuff(sp_Answer) code isif sp_Answer = “Yes” then do this elseif sp_Answer = “No” then do that endif; HOWEVER, in the case of the Logoff Procedure, this doesn’t work. Specifically, I want to ask the user if they want to save the changed data, wait for them to respond, then save (or not) and close. Old (WinUI)

I want to clear the memory used by AIMMS after running an execution. I delete the GMP but still huge amount of RAM is occupied by AIMMS after the run. So I have to close and open the AIMMS to have a fresh start (i.e. with a clear RAM memory). Is there anyway to clean the RAM used by AIMMS after the execution so I do not need to close and open it again and again? Thanks in advance. 

Hello everyone!I’m reaching out to know how can I use multiselect in showing nodes and arcs in my network map. It is part of my project to make the UI interactive, however, I’m having difficulty doing so. I have tried testing if the same multiselect-table interaction can also work here, but it doesn’t. Any tips or examples you can provide?Thank you!

Hi,In my case, each plant has a different set of tanks, and the user is able to select one plant at a time. Whenever user selects a plant, the inventory level over time for each tank in the plant is shown on a graph - and the graphs need to be placed on top of each other. This was a behavior that could be achieved in WinUI easily, by creating an Indexed Page object and identifying a parameter for the Index Rows.  I am wondering if there is a way to achieve the same behavior within WebUI?

Hello everyone, CPLEX returns optimal solution for small instances of a MIP model. But when try to solve a larger instance, CPLEX return a local optimum (solution checked by a heuristic). The model is MIP with a number of Big-M formulations that are replaced by Indicator Constraints. For one of the large instances:  # of constraints: 2086337 #of variables: 1122331 (66225 int)  #of none zero: 7223176 It takes 53557 seconds for CPLEX to close the optimality Gap. Any idea? please share your thought.

Hi. I am trying a generate a plot of optimality gap vs solution time. For that, I am trying to retrieve incumbent solution, best bound and solution time after every 5 iterations. But, for some reason, I am having issues with callback and I don’t get anything retrieved. Attached herewith are the images giving implementation of callback operation. Could anyone please tell where I am going wrong? Thanks,  Sujit

Hi everyone!   Is there a way to change if I want to show or not the unit and the number of decimals by parameter?   Example:    My wish: 500     |     0.00%   Thanks.

Hi all,I’ve seen here and there some things mentioned on the following items below, but I lost track on the latest developments. Can someone share a status update on them?Have the capability to specify file decimals per identifier (instead of per widget) ? Support for unit (parameters) in WebUI ? Library support for WebUI , i.e. that some WebUI parts / pages become shareable across different AIMMS apps Visible/hidden option per identifier in widget settingsDepending on this I might post an improvement idea for the backlog.Thanks,Joost 

Here I find a problem: when I use GMP::Instance::CreatePresolved to solve a MathematicalProgram , the solution I get belongs to the Presolved MathematicalProgram rather than the orignal MathematicalProgram. My code is as follows:MyGMP := GMP::Instance::generate(MarketDA);MyGMP_Pre := GMP::Instance::CreatePresolved(MyGMP,"GMP1");MySolver := GMP::Instance::CreateSolverSession(MyGMP_Pre , "Solver1" , 'CPLEX 12.3');GMP::SolverSession::Execute(MySolver);GMP::Solution::RetrieveFromSolverSession(MySolver , 1 );GMP::Solution::SendToModel(MyGMP,1);There is an error report on the last line shows the solution 1 is not exist. Is it possible to send the solution 1 to “MyGMP” model ?

Hi all, is there a way to save your project from a procedure (as can be done with cases: https://how-to.aimms.com/Articles/258/258-save-a-case-from-aimms-procedure.html)? If not, is it possible to let AIMMS automatically save the project each time a procedure is run?  

Can anybody suggest how can i eliminate the following error? Warning: After 66905692 iterations CPLEX 12.8 terminated and leastcost is still infeasible. 

The WinUI has a super obvious tab for the Legend of a linechart. But there seems to be NO way whatsoever to display the legend (or anything that will work as a legend) on a WebUI linechart. I even tried the (seemingly obvious) solution of using a legend widget. If this will work, I can't figure out how. Is there a way to show the legend? And if you don't have on yet, is there a workaround and do you have it in the plans in the future?

 I was wondering if there is a programmable way to unpack an aimmspack file, e.g., MyAimmsProject.aimmspack, without launching Aimms? Looking for something likeAimmsCmd.exe /Unpack "MyProject.aimmspack" -o "Path\To\Unpacked\Project"

Just wanted to know if it is possible to style the buttons in AIMMS based on information from the model. What I have in mind is allowing the user to open for example 25 different pages (e.g. for different inputs) by providing 25 different buttons.I would like to style these buttons in such a way that if the input that corresponds to the page this button opens contains an error, the button should be red or I would like to include a red Error symbol (think might be possible with unicode and variant selection?) on that button and if there are warnings, I would like to make it yellow or have a yellow warning symbol. Green checkmark could indicate there are no issues with that particular input. It could also be that buttons to open the 25 different inputs are not the best way to this from UX perspective. If that is the case, what would you recommend?

Frequently we run into the limitations of resizing widget. Here is one concrete example which could be solved if we can hide the table header.   In our application we have a table with a 1-dimensional parameter with 4 items. With a table widget of row height 1, we don't see the last item unless we scroll. With a table widget of row height 2, we have a lot of redundant white space we want to use for something else. All items would be visible in the smaller widget, if we could hide /collapse the header. Is there is a way we can remove the column headers via CSS?   As a side note, I believe grid we are limited to when placing widgets is too coarse.

Dear AIMMS Team, I am a PhD student in the UK and I have been trying to solve a non-linear non-convex optimisation problem with different solvers for a Journal Paper. The following are the CPU details: Intel Core i7 2.2GHz, 16GB RAM memory, 64-bit operating system. So far the solvers CONOPT 4.0 and IPOPT 3.11 have been able to solve the case without problems. Unfortunately, when I use MINOS the following error appears: Errors/Warnings Warning: Model status 13: Error no solution, Solver status 9: Error: Setup failure (see message window). Message Window For the MinCost 39239 columns have been generated of which only 31245 are non-empty. Calling MINOS for NLP of 34726 rows, 31245 columns and 109867 non-zeros. Calling MINOS to solve NLP model 'MinCost' and minimize GenCost. Generation required 0.406 seconds. MINOS error: Not eno

Is it possible to export an AIMMS model to .aimmspack file from Azure Devops Pipeline?Goal is to generate the .aimmspack file from the Azure Devops Pipeline after the model source files have changed.  I was hoping to run aimms.exe --export-to without have a user signed in, or storing the private license files in a public place.From Documentation:Through the --export-to option you can instruct Aimms to create an encrypted end-user project either packed to the .aimmspack file specified, or unpacked into a specified folder. When using this commandline option, Aimms will use the export settings as saved by the previous call to the File-Export End-User Project menu. You can use this commandline option, for instance, within the context of a continuous integration server, to automate the deployment of your Aimms application after new commits have been pushed to the version control repository managing the project. Specifying the unp