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I’m trying to see the nominal coefficients property for a variable. I have CoefficientRange property selected and my  Calculate Sensitivity Ranges is ON. However, it doesn’t show the property when the problem is solved with AIMMS Linear Presolve being OFF? Please advise. Here’s the documentation I found:.NominalCoefficient Definition: When the property CoefficientRange of a variable is set and the option Calculate Sensitivity Ranges is not set to off a coefficient range sensitivity analysis is conducted such that the optimal basis remains constant. As a result of this analysis the variable suffix .NominalCoefficient contains the nominal objective coefficient value.

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 Community;According to our current Aimms project deployment practice, we deploy an end-user aimmspack file on Windows/Linux machines. The host Windows/Linux machines have a “normal” (normal means not Aimms-Pro) Aimms installed with an end-user licence. The projects are executed using Aimms.exe/AimmsCmd commands.However, we have recently developed a webui for a new project, we are now wondering if we must deploy using Aimms-Pro to have the webui working in the production environment? Can we install Aimms-Pro on Linux servers (I understand from the documentation that it is supported only on Windows servers)? If it is possible to access webui using “normal” Aimms (we prefer linux deployment):How can we define a static port for webui URL? We want to run aimms with --hidden flag and access the webui using a static URL. 

Hi, My model took more than 14 days to run on i7 core computer with 16GB RAM. And it still does not give an optimal solution yet. What will happen if we stop AIMMS during the middle of running a model when the solution is not optimal yet? The gap in progress window shows 38.2% for 10 days (see attached picture), then it drops to 38.1% on day-13. From what I understand, the gap is the difference between a best known solution and the best bound. If I set the gap to certain values, which part of the model will be affected? Will all the constraints be satisfied/evaluate? Or will AIMMS only satisfied half of the constraints? For your information, my objective is to maximize the preferences of the lecturer. My preferences parameter has the range values from 1 to 5, where 1 is least preferred while 5 is the most preferred.  Can anyone help me? Thank you in advance! Gap on Day-12  

I studied the ‘’One hour beginner's course‘’ and tried the example. But there were something wrong with the number displaying. I can’t see the results in the table.(just as the second picture,there is blank in the table)

HiI am getting the following error while executing my code in AIMMS.ExcelSetActiveSheet(data.xlsx, Sheet1) unable to get a handle to the workbook: Could not open Excel.It would be grate if you can help me with this issue. 

hello,I was studying the tutorials provided by AIMMS and I came across a Production Model in the PDF Document for AIMMS for Professionals Tutorial. I’ve tried to open the file to see if it works but I come across the following errors as attached and it will not let me execute the model.  The zipped folder with the model has also been attached for your reference. Thank you for all the help!

Hello dear AIMMS Community, currently im working on a simulation of robots driving in a parking garage and charging electric vehicles.The first step is done and it is kind of working, but i have currently two major problems. even if i am not putting any demand on the parking lot the robots drive to the lot and “simulate” charging an electric vehicle.  → i tried to find a solution in the community, but i was not successful. Is there any possibility, any constraint which could make  the robot not to service/drive to that parking lot while Demand(i)=0. As you can see in the picture: even if i put Demand of almost every parking lot=0, the robot drives to all the places, before going back to the depot.   Another problem is, that i want to make the robots drive on a specific route,  shown as yellow in the picture/simulation.  → Is there any chance of making the robots drive a minimum besides the yellow route? My thought is that, despite being able to create that, later in the mathimatical pr

Hello,I haven’t finished my master's thesis because I need to install AIMMS in Amazon Web Services (to have a strong processing capacity, and I have US 10.000 credits). To do that I need to enter the Subnet of the university to activate the license through a virtual machine on Amazon (EC2). This has been impossible.Some help would be amazing or another solution.BP

Dear All,I have a question on how to limit the range of an index and since I’m new to Aimms I can’t find a proper solution. I just want to limit certain indices to a certain range for a specific constraint.First example (Constraint):Index Domain:tDefinition: e(t) <= e(t-1) |t<Tmax |t>TminError Message:In an inclusion only the middle term is allowed to contain variables, however in the inclusion e(t) <= e(t-1) $ t < Tmax $ t the left term contains variables. Second Example (Constraint):Index Domain: (i,j,k,t)Definition: r(i,j,k,t) <= o(i,k-1,t-1)*RM(i,j) |k>1|t>1Error Message: The operators <= and > should to be the same for numerical inclusion (or use parenthesis). As I’m new to aimms I dont seem to understand the principles properly. May someone point me to the right way to do this?Thank you very much in advance!Best RegardsJonas  

I was wondering if it is possible to change the shape of the node on the map from a circle to something different, e.g. a square or triangle? I am already using color coding to indicate allocation of store locations to warehouses, the shape is intended to differentiate between 3 different types of stores.Using of icons or alterntative stroke colors doesn't really work, because the nodes need to be quite small. But I am also interested in any other suggestions to make it work.Thanks!

Hello everyone, Since I’m starting on AIMMS, I have two little questions : One of my index, called t, goes from 1 to 15. But for one of my constraint, I need that it goes from 1 to 14. How can I express that on AIMMS ?  In order to get the bound after the addition of cutting planes by the solver, my teacher told us that we can limit the number of branch-and-bound nodes to 1 by going to menu solver options. The problem is that cannot find this menu on AIMMSCould you help me ? 

Can not deactivate because of 601 Error 

I have several problems but I think they are related to each other. For all my constraints I get the warning “The index “i” already has a scope” and I also get this warning when I want to enter my data. Also when I want to specify the objective for my Mathematical Program I get the warning: “Expecting a scalar identifier (no free indices)”. I’ve added pictures of one of my constraints, the warning from the Mathematical Program and my Set where I believe the problem might be with the index i. But I don’t really know how to fix it so if someone could help me I would be very grateful.  

Hi, I am going through AIMMS FOUNDATION COURSE, where trainer asked to declare Set Index as 1, 12 when i am doing that getting error that “The symbol '1' is not expected but a symbol like 'identifier' is expected.” 

Hi all,my question relates to the font size of axis labels when enlarging the respective widget to full-screen mode. The font size is fine on the normal page when the widget is its standard size. However, when zooming the widget, the font size stays the same, making it very hard to read.Especially when making screenshots of the charts to use in e.g. business presentations, it would help if we can adjust the label size when enlarging a widget.Any suggestions as to how I can do this?Thanks in advance 

Dear Community; We are working with some MILP problems where we need to identify the ShadowPrice of some constraints. These constraints are made up of both binary and continuous variables. As the duality is not well defined for MILP problems, one method to find the ShadowPrice is to run a LP fixed model right after MILP solution. I see that AIMMS provide ShadowPrice by default for MILP problem when the variable property “ShadowPrice” is defined. We need to know how AIMMS calculate ShadowPrices for MILP problem? Does AIMMS use a method similar to post MILP fixed LP execution? A quick additional question: Is it possible to identify and set all Bianry and Integer as “nonvar” (i.e. if var is Binary then var.nonvar := 1) -- the idea here is to manually prepare a fixed LP? I do not see how AIMMS support fixed LP preparation and its execution. Thank you;Amrit Gill

HelloI have created another model for practice on AIMMS for inventory optimization. There are no errors during compiling however I am getting the attached error while running the procedure in the Main Execution part. The model and the error have been attached as a zipped file for reference. Thank you for all the help! 

Dear All, My name is Mohamad Khaled and for my university research project I am using AIMMS to model a 3-echelon Pharmaceutical Supply Chain model. The current model I’m trying to define and solve is a simple one compared to some of the models I have seen here. I have two issues with my current model: The first issue is that the pharmaceutical products (AKA medication) has an uncertain demand which I am not able to properly define in the project despite indicating the index domain, using the uncertain option in the property setting and defining the box function with an upper and a lower value in the region area. (I attached a screenshot of the demand parameter with the descriptions and region and another screenshot of the current “nominal” data of the demand)  The second issue is the wastage/expiration of the medication. I have defined a shelf-life variable and respective constraint, however, I couldn’t get the shelf-life variable to be used in the wastage constraint as the following w

Hello,I am solving small MINLP problem using BARON solver to find the ‘optimal’ solution. But for such a small system, 8 hours passed and I have not got the solution yet. My question is: why this solver cannot find the solution after such a long time? Is this because of the way I implemented the model? (If so, I am attaching my code here to let you know how I did it). I would appreciate it if you could help me solve this problem. Thank you!Regards

Hi, I would like to know how I can give an initial integer solution to a MIP solved with CPLEX. I found this link on the topic but I’m not convinced about the option it suggests for CPLEX in particular “Advanced basis” sounds like a setting to warm start an LP, not a MIP. I’m also not sure how to actually give my heuristic solution to CPLEX after that.https://how-to.aimms.com/Articles/108/108-kb11-mip-initial-solution.html.I also found this related question, but the link in the selected answer seems to be broken: https://community.aimms.com/developers-math-or-programming-39/how-to-start-solving-with-an-initial-solution-466.Thanks

I have created a model on AIMMS for production. There are no errors but still we are not getting any result. I tried multiple modifications, but I am stuck. I am attaching the model for reference. The formulas have not been used anywhere else except for the attached files.

I would like to freeze the left most column in one of my tables. This column contains an identifier with no values in other columns. Is this somehow possible via CSS or some AIMMS logic I am not aware of?

I run Power System Optimizer (PSO) developed on AIMMS. The current version of AIMMS we have is 4.30.5.814 on the windows server. The software ran with no issues till last week. However, after probably the server update, AIMMS crashes each time I read input files and throws the following error: the thread tried to read from the virtual address for which it does not have the appropriate access. I am not sure what the issue is as the input folder has complete privileges for read/write.

Dear Community, I plan to work from the Python workbench to call AIMMS to execute the optimization for my research project. I have some questions about linking AIMMS to Python: 1) How do I execute the AIMMS file by calling it from Python? 2) Will the results be written back to Python? Or, how can I export the results to the Python workbench? Thanks in advance, I look forward to executing my research with AIMMS... Best regards,