Optimization Tooling

In this article, we explain how to use the asynchronous solver sessions in AIMMS to solve multiple mathematical programs simultaneously, each using its own CPU core. Why use asynchronous solves? The current engine of AIMMS does not make use of the multiple cores that exist in most modern computers. This means that even if your computer has multiple cores, AIMMS only uses one to execute your project. However, some solvers support using multiple cores. This means that if you are solving a large LP or MIP problem, a solver like CPLEX or Gurobi use multiple cores in your computer to solve your problem. Read more...

The CPLEX solver has many options that influence the way CPLEX solves your model. For certain types of constraints and/or models, you can make an educated guess about which combination of options works best for your problem. However, sometimes you need more help. To help you out, CPLEX has some automatic tuning options. In AIMMS, you can access this CPLEX tuning tool via the following two functions: code:GMP::Tuning::TuneMultipleMPS https://clipboardjs.com/assets/images/clippy.svg code:GMP::Tuning::TuneSingleGMP Read more...

You can use different indices to refer to the elements of the same set. Suppose we have a set, code:Cities, and a parameter, code:Distance. We want to define code:Distance over 2 dimensions (code:from and code:to) for the same set, code:Cities. If you didn’t know that AIMMS can handle multiple indices for a set, you might create two new subsets code:CitiesFrom and code:CitiesTo, containing all elements of the set code:Cities, and each with its own index. Luckily, you can just assign multiple indices to one set. Read more...

A brief overview for using AIMMS Command Line Tool. In the integrated environment, or on a Linux system, you can control an AIMMS project externally using a command line tool. To start using the command line tool open the terminal and run code:AimmsCmd ExampleProject.aimms. Read more...

By default, AIMMS asks you whether you want to save changes to data when you close your project. This behavior depends on which data categories and case type are currently active. You can also use the data change monitor functions to check when there are changes in a given subset of identifiers in your model since the last time you checked, based on a data category and case type. Read more...

Hi! We were able to execute the model already but we're having warnings that the result for this column is similar with the other column. Take for example the constraints 22 and 26? How do we code the "summation"? Sorry I'm just a beginner and I have no one to teach me and I only have a month to study everything because the deadline is just for 2 months. Our model in AIMMS can be downloaded here: https://drive.google.com/open?id=1pUgymOpS0-oJLxc_IU6tjt7YEiKkHqmW

When solving a stochastic program, the results can be accessed using .Stochastic. However, I cannot find this data in the WebUI when trying to make, for example, a table showing the objective value of the stochastic program for each scenario. My question then, is this: how do I show the values of both Decision Variables and the Objective Function for each scenario, resulting from solving a Stochastic Program?

Hi, I have this code that prints the variables to a text file. code:for IndexVariables do put(IndexVariables); put // ;endfor; This prints only the first 12 characters of each variable. Why is that? Thanks, WM

Hello everyone, Does AIMMS has a feature that allows me to see the inedex, parameters, variables, obj function and the constrains? I basically want to view the model in a simple way. Thanks!

I've just about got a handle on the css "rules" for the widgets, but the buttons for the new dialog pages don't follow those rules, it seems. I've tried a gazillon permutations of .dialog-open .dialog-page-container .ui-dialog-buttonpane .ui-dialog-buttonset button:last-child button .ui-button .action-cancel .ui-widget .ui-state-default .ui-corner-all .ui-button-text-only How can I change the button color, text color, etc? At this point the only thing that changes anything is code:.theme-mytheme.dialog-open .ui-button-text and that only changes the background around the text itself, not the button background. Thanks!

Hi there, I am trying to implement some form of heuristic for the TSP where I'm decreasing the size of the model by restricting the declaration of variables X(i,j) to those combination (i,j) for which j belong to the, say, 10 cities nearest to i. Here X(i,j) is an binary variable indicating whether or not edge (i,j) is in the tour. I created a subset of the cities to find the nearest neighbors of city i, but how can I implement it in the model? Do I need to add an extra constraint or? Added you'll find the code of my AIMMS project. Thanks in advance!

Hi! I encountered this problem as I try to recall my data from an excel file. The error says: ExcelRetrieveParameter(FINAL DATA.xlsx, N(E), B16:DQ16, , 0) failed: Actual cardinality (0) of domain #1 is smaller than specified cardinality (120). what should I do?

Hi! I would like to ask what this error means and how I can solve this: ExcelRetrieveParameter(FINAL DATA.xlsx, nC(v,T,w), C3:ALN22, , 0) failed: The dimension of parameter "nC(v,T,w)" is 3. It must be equal to or smaller than 2. I hope anyone can help me with this. Thank you!

I'm a beginner and I know nothing about programming so Im just basing everything from the user manual. I have a parameter with a "nC' as identifier and index domain: v,t,w. The problem is when I try to save it there's an error saying "The symbol ";" is not expected." How do I fix this?

I need to mask my indexes names in WebUI tables the same way is possible to do in WinUI pivot tables using an string parameter. How I can do it? Example: Set Frubas := { '1', '2', '3', '4'} Ps_DescriptionFrubas('1') := "First" Ps_DescriptionFrubas('2') := "Second" ... In my WebUI table it appears as 1, 2, ... and it should appear "First", "Second" ...

I'd like to launch WebUI automatically upon opening a project. I can't seem to locate the webui::pr_OpenWebUI procedure. Is there one? Thanks! ~Bon

Hi all, we like to share three insights that help to create better page layouts, in order to create more user friendly apps. Any thoughts? Pls share in the comments. Tip 1: Tell a story on your page, by matching the placement of widgets to your user's ideal flow. Next, order your widgets from top left to bottom right. Bottom right is also a great place to put a button to go to the next step in the flow. Tip 2: Avoid dead ends in your app. This will confuse the user as he may not know what to do next. Making a button appear to go to the next step is a great way to keep the user flow going. Tip 3: Make an attractive home page, since we all know that first impressions count! Consider what widgets to place here that give some immediate value to the user. Maybe the results form last time, maybe a map, maybe the progress of the app, or what is expected from the user.

Hi, How can I empty all sets except 1? I only want to empty self declared sets. I tried it with a for loop. However I have some trouble comparing the name of the set with a string. Kind regards, Wiet

never mind, problems was not with session arguments Hi, How to set multiple session arguments? Where has this been specified in the manual? Thanks! WM

The help feature for using a function is very nice: The auto-populate for inserting an element is also swell. But how about some kind of auto-fill for the functions themselves? Is there a keyboard shortcut for that? Thanks! ~Bon

Hello, I have created two histograms using "Histogramcreate" where the "HistogramSetDomain" are the same but the frequencies observed (using "HistogramGetFrequencies") are different. I have also drew the plots of the histograms separately. I am wondering if it is possible to show the two frequency histograms on the same plot? I appreciate any help in advance

Dear All, Wanted to convert two IF loops in a linear form. Suggestions/Guidelines are requested. Thanks.

Hello 1- I will try different constraints for my model. For example, I want to disable all constraints and show the results. I tried to created parameters as a below; parameter: IsDisable , range=integer Constraint: MyConstraint , index: (i,j) | not IsDisable But in index section in MyConstraint: " t | t>=2 " I could not add the " | not IsDisable " 2- Also How can I write the solution to excel? Could you please help me? Best Regards.

Hi there, I'm trying to implement some sort of production optimization model using the concept of column generation. In the declaration section of AIMMS I declared the master and pricing problem, however I am not able to use the 'ShadowPrice' property of one of my constraints, i.e., the suffix turns red if I want to use it in my pricing model. Nothing I am trying does look like to work out and I can't find any other questions like this. Ïs there anyone who could help me out? I would appreciate this very much! Thanks in advance! Attached is a .zip with my model.