Solved

Hello everyone,This is my first time using AIMMS for academic purpose. I was facing an issue with the WebUI the is not downloaded correctly, then i found a post here in the community suggested to download this https://library-repository.aimms.com:443/libs/69378F70-E906-486F-8F2C-1D606AEB9669/24.11.2.3/x64_vc143_Release.alib in MS Edge browser. After i downloaded it, then a new error shows with following error message:"Failed to retrieve the latest WebUI version from the repository(Error: Error resolving hostname library-repository.aimms.com: No such host is known.)"Does anyone face this issue, what should i do in this case?Thanks!

Hi everybody,  Recently I updated AIMMS to version 24.6.1.6. Now I get the error message “The element 'abort' is not in the set "AllIdentifiers", see also the option warning_explicit_element_not_in_set.”. Does anyone know how I can solve this error?  It happens when I use a call back function and want to assign “abort” to the CallBackReturnStatus.  Thank you in advance!

Hi everyone,I'm currently working on an academic project that requires accessing and adapting a legacy model originally developed in AIMMS 3. When I try to open the project using the current version (AIMMS 25.4.2.1), I get a message saying I need to first open it in AIMMS 4.90 or earlier to convert it to the new format.Would anyone happen to have access to the AIMMS 4.90 installer (or the latest version prior to it that supports AIMMS 3 project conversion)?Also, does anyone know if a license tied to version 25.4.2.1 is compatible with AIMMS 4.90? Or would I need a separate license for that? If so, how can I ask for it?This is for academic, non-commercial research. Any help would be much appreciated!Thanks in advance,Hugo

I cannot find the PreSparsify option of the Gurobi solver in AIMMS. (Parameter Reference - Gurobi Optimizer Reference Manual)Is there a particular reason that this option is missing? otherwise, is it possible to add the support for this option in the next update? 

I found there is a strange phenomenon that the progress window shows a infeasible problem with optimal status, just like this:So, I want to know the program is infeasible or not and the reason caused this. Besides, the program window shows the best solution is na but I found the objective value in math inspector is non-null. 

I found the CPLEX QP method contains Primal Simplex. Theoretically, Simplex method can’t be use to solve QP method, because The Simplex Method works by iterating through the vertices of the feasible region to optimize a linear objective function. However, quadratic programming problems involve a quadratic objective function. Due to the curvature of quadratic functions, the optimal solution may lie in the interior or on the boundary of the feasible region, not necessarily at a vertex. Thus, the Simplex Method cannot directly handle quadratic objectives. So, I wonder if the Primal Simplex could really solve the QP problem, or it can only solve a part of them. Besides, I want to know if there is any hidden danger of using simplex method to solve QP problems.

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 ?

 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"

 Hi,Say I have the parameters shown below.I am using the “exists” function to check whether there is a “1” for each category during the time range from 1:00 to 5:00.While “exists” returns a logical value indicating whether a “1” is found, it does not return the index. Along with using the exists function, how can I also find the indexes corresponding to the “1”s in my parameters?Thank you! 

Hi,Using the AIMMS version 24.5.9.4. I have put pretty tight conditions on my index domain on purpose, but the model generation phase takes about 20 mins and # variables on the Progress Window reaches up to 55 million, which is a very surprising number for me because of the reason above. Then right before the solve process it instantly decreases to 679K, which is much closer to what I’d expect. Then the solve process takes only 5 secs. So 20 mins for the model generation, and then 5 secs to solve, but what I am really wondering is why would the number of variables inflate this much and then instantly decreases right before the solve? Can anybody explain the possible reasons?Please see the pics below.Best,Gorkem    

Basically ill provide here the formulation:We have set t →       t ∈ T = {1,2,...,tn}           ∀t ∈ TAnd we need to create and use set tau where tau stands fortau →      ∀τ =t+1,...,min(t+Li −1,tn) Please, it would be so helpful if someone could provide a solution. Thank you so much.

Hi,I have a parameter read from a CSV file. The first column contains the index list, and the other three columns contain the data. However, I need to use the second column as a second index to differentiate between each hour after the parameter is loaded. I was wondering how this can be done in AIMMS. Please note that using the second column as an index in the first place when I am reading the the CSV file is not viable due to other constraints. Please see the attached photo for a better understanding of the issue.Thank you. 

Dear community,When I try to execute my model, I receive the following message:Warning: After zero branches CPOptimizer 22.1 concluded that ModelObjective is infeasible.I don’t understand what is causing this issue or how to resolve it.I am aware that some parameters are currently unused, but they will be needed for future adjustments once this first part is working.Does anyone have any insights on what might be going wrong and how I can fix it?Best regards,Louis 

Some of the files shared are json files and aren’t accessible.I also tried to look up pre-existing files and the tutorial for beginners after installing the software, but it throws an error. How do I proceed as it is my first time using AIMMS and the deadline is nearing 

I have met such a problem: When I use “GMP::SolverSession::SetOptionValue(SCUCSolver,"Polishing_relative_MIP_gap",0.0001)” to Set the Gap of a MIP Mathematical Program, the solver returns a solution with gap of 0.99% which is larger than 0.0001. I have also tried to use “option MIP_relative_optimality_tolerance” but it still didn’t work. How do I so this? Thank you

I Want to solve a MIP Mathematical Program without some of the constraints by  use GMP::Row::Deactivate, but the Program Status return Integer infeasible. However, when I Replace GMP::Row::Deactivate with GMP::Row::Delete, the Program can be solved. I could’t understand the difference between GMP::Row::Deactivate and GMP::Row::Delete. My code is as follows:SCUC_Instance := GMP::Instance::generate(MarketDA_MP);GMP::Solution::DeleteAll(SCUC_Instance);SCUC_InstancePre := GMP::Instance::CreatePresolved(SCUC_Instance,"SCUC");GMP::Solution::DeleteAll(SCUC_InstancePre);NFGConstraintsSetRowNum := GMP::Instance::GetRowNumbers(SCUC_InstancePre, NFGConstraintsSet);!NFGConstraintsSetRowNum is a Subset of Integer with index as nk   for nk do        GMP::Row::Deactivate(SCUC_InstancePre,nk);    endfor;endif;NFGVariablesSetColumnNum := GMP::Instance::GetColumnNumbers(SCUC_InstancePre, NFGVariablesSet);!NFGVariablesSetColumnNum is a Subset of Integer with index as nv    for nv do        GMP::Column::F

Dear AIMMS expert,Is it possible to display several variable data with a single parameter?Thank you very much.

I have multiple math programs, each related to a different energy supply sector.. I want to keep their development and version control independent. Is making them into libraries a reasonable way to combine these otherwise independent math programs? 

Good morning all. I just brought out an old program I have written over a year ago to run it and it gave an error:‘The CONOPT 4.1 library has not been loaded because: Solver initialization failure.’Please, what can I do to remove the error. Thank you.

Hi communityWe use standard Excel functionality to download a file of the following format:Then we try to reupload this file after having made the following adjustment (we manually adjusted the columns A and B and copied the values in A2 and B2 from other Excel): However, this reupload resuts in 0 changes being made to the table in the WebUI. What could be the reason the reupload fails to read in the 1000?

Hi, With the center of gravity tool, I want to find optimal recycling/ production centres. I was wondering how to use the tool for finding the optimal production locations. Now, it seems like I can only determine optimal warehouse centre locations. Moreover, I was wondering whether it be possible to leave out warehouse locations at all. So, just include the suppliers, production / recycling centres and customers. Also, I want to add a specific constraint on the minimum that has to be produced in total. Thus, not a minimum constraint for a specific recycling/production facility but a constraint on what all facilities together should produce (outflow of all facilities together equals a number) Thank you!

I am running AIMMS 24.6.3.3 with an academic licence on a macbook air M2 through parallels.I would like to include AXLL in my project, but when opening the library manager and trying to access to the library repository, I get an error message that doesn’t provide any information on how to solve the problem: Unable to get the list of available libraries from repository. How can I possibly solve? Or alternatively, is there a way to use AXLL on my setup without accessing the repository?

I want to to solve several instances of a model with modified input data. This varied input data usually only affects the coefficients; but, it might affect the number of variables and constraints as well. Ideally, the varied instance of the model should use a warm start from the last solution to reduce run-times. I am a bit familiar with GMP functions. However, I am not sure how to effectively implement such procedure. I was wondering if AIMMS has something similar to Gather-Update-Solve-Scatter (GUSS) syntax in GAMS. I would appreciate your comments :)

Use Case - I have a group of customers from - state/provinceI want model to pick only - 1 DC out of N DC ( i.e - all customers in that particular State/province -should get material from 1 DC (same DC))N.B- I have - different drop size for each customers & also cost is different - basis DC & Customers.Question - How can we model this case?I am exploring the single sourcing - from customer product table & location product table 

Hi,I was a production planner at a rotational molding factory, and now I try to model this environment in Aimms by using the example of the machine shop scheduling problem.For my model I only need one extra ‘dependent’ variable → a variable that tracks starts and ends of products on a machine. The reason is that starts/ends of a product on a machine involves set-up cost, and I want this to be a penalty in the TotalCostOfStartingOrders.So I created the binary variable DoYouStartOrRemoveAProductFromAPosition(m,a,s,p,pn,i_dc), in where m is the machine (2 machines), a is the arm (each machine has 3 arms), s is the side of de arm (each arm has 2 sides: up or down), p the position (each side has 3 positions), pn is the product name (the model contains 12 products) and i_dc is the daily calender in workdays (66 workdays).This binary variable is defined by three contraints:DoYouStartOrRemoveAProductFromAPosition(m,a,s,p,pn,i_dc)<=(DoYouHaveProductionOfAProductInAPeriod(m,a,s,p,pn,i_dc) + D