Solved

Here I found the function GMP::Instance::SetMathematicalProgrammingType is not able to change mathematical type of a instance from MIP to QP. Is there any way to achieve this without generate the instance again?

Hi, I have constructed a MILP with the size of:______________________________________________________________CPU model: Intel(R) Xeon(R) Platinum 8370C CPU @ 2.80GHz, instruction set [SSE2|AVX|AVX2|AVX512]Thread count: 24 physical cores, 48 logical processors, using up to 48 threadsOptimize a model with 1081904 rows, 968127 columns and 12886704 nonzeros_______________________________________________________________I am using an older version of AIMMS: 4.92.12. I am using the GMP library to generate and solve my instances.I solved 10 instances with each 4*5=20 different parameter settings (so 200 solver sessions in total). My procedures are set up as follows (simplified version): Import instances → Generate 4*5 =20 versions of each instance → start asynchronous execution of 20 instances → WaitforSingleCompletion → Save individual instance data. I use a virtual machine with 24 cores and 48 threads. I use Gurobi as a solver and have a WLS licence for 200 parallel solver sessions. The thre

Dear,I am trying to use aimms.py in order to run a AIMMS model from python and parse and receive output. I created the following python script based on the package: aimmspy · PyPI. import osfrom aimmspy.project.project import Project, Modelfrom aimmspy.utils import find_aimms_path aimms_bin_path = r"C:\Users…..."project_file = r"C:\Users…..aimms"# input_file = r"C:\Users....txt"results_file = r"C:\Users....csv" project = Project(    # path to the AIMMS Bin folder (on linux the Lib folder)    aimms_path=aimms_bin_path,     aimms_project_file=project_file,    license_url=R"wss://licensing……..") my_aimms : Model = project.get_model(__file__) my_aimms.GuiReadData() After running the script (with proper paths and license), I get Unable to load IBM CPLEX library. Exiting.I tried to change the solver within AIMMS but still the same error occurs.  Is there anyone that encountered the same issue? I look forward to a reply.Kind regards,Jesper 

Dear all,Is there a probability function in AIMMS?For example, I want to calculate:where:x: The capacity of power plant to be constructed (MW)y: Installed capacity of power plantF: force outage rate of power plant Thank you very much…. 

Hi, Let’s say I have a set consisting of 5 elements such that: Set1 = {‘A’,‘B’,‘C’,‘D’,‘E’}.How can I move some elements to the end of the set. For example:Set1 = {‘A’, ‘D’,’E’,’B’,’C’} Thanks!

Our users want to be able to store case files locally on their computer and reupload to the cloud environment at a later stage. It looks like the WebUI data manager does not support this requirement. What is the best way to enable users with such a feature?

Hi,I am wondering whether it is possible to read the Jobs screen data from the PRO server into an AIMMS project. I am especially interested in the Process ID but would like to read all the information if possible. See below.Best,Gorkem

Can anyone tell me if there is a way to write profiler output to a file?     An external application is invoking AIMMS from the command line multiple times during its run, so it would be useful to generate this file 

Hi, So I have a very long model(.ams file) of 14MB. It is taking forever for the model to create and run. The window is always in a not responding mode and the status always stays in compiling. Can anybody help me get this long model running?Immediate help would be appreciated. This is the scalar version. Thanks 

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