Topics about getting started or leveling up as an AIMMS developer. Datalinks, AIMMS language, building apps...
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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
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.
At AIMMS User Content we made a choice regarding the naming convention to be used and would like to share the considerations we had to derive at our choice. What do you think? What are the considerations you used for the naming convention you use?see Identifier naming convention
When you solve a Mathematical Program in AIMMS, the default behavior is that AIMMS will let the solver solve the problem to (local) optimality. There might be situations where you want to stop the solve procedure after a set time period, or once a solution within a given percentage of the best value is available. This article will show you how to apply different stop criteria to a 'solve' statement in AIMMS. [url=https://how-to.aimms.com/Articles/172/172-use-stop-criteria.html]Read More...[/url]
I run Power System Optimizer (PSO) developed on AIMMS. The current version of AIMMS we have is 18.104.22.1684 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,
Why do we need docs? You may be thinking – I’ve got a million things to do before I can deliver an app to my client, I don’t have time to write documentation!But consider a time you’ve downloaded a tool, or tried to connect with a component library, or even tried to put together a piece of furniture and discovered that the documentation is impossible to understand or, worse, not there at all. Consider another time where the documentation was easy to use, and you probably don't even remember reading it – you just followed the directions and it worked. Which situation would you like your user to face? This also applies to a time when you’ve tried to work on a group project, or taken over a project after someone else. Isn’t it nice when someone explains what they’ve done, how, and why? Docs for your team This is documenting how you made the app in the developer platform. Write them for anyone who may be working on your app, now or in the future. Even if you're a team of one, it's a good
Hi there,I’m having an issue with AIMMS which is preventing the advanced text editor from working.When I launch AIMMS I get a Windows pop-up asking to install the Microsoft .NET framework 3.5. Then in AIMMS I get the error:Unable to locate the SyntaxEditor .NET assembly, falling back to ordinary editor.However, my machine is already operating the .NET framework 4. I’m using a work machine so am unable to roll back/install the older framework.I’m running Aimms-22.214.171.124-x64-VS2017.Has anyone had this issue?Any ideas on how I might be able to get it working?Thanks for your help!
In our team, we are working on a linear energy system model which is expanding every day. We use the LP Gurobi solver with multi processing. Currently, it has 250M non-zeros (after presolve) and we think it will grow to more than a billion. If the computational capacity (let's say several hundreds GB of RAM) is present, is there any limitation on the problem size on AIMMS side?In particular I am interest in any limitation on number of variables, constraints, or non-zeros? or any limitation on the capacity of committed RAM or number of CPU cores for parallel computing?
It is probably very simple, but i cannot figure it out and i need to get it done asap. Really appreciate any help!I have created a project that runs and gives me solutions. Now, i need to create another version of my model with major changes, but to make it faster i would like to “save as” the entire current project and then start making my changes. the “save as” menu only makes another copy of .ams file within the current project, but doesn't make an entire new project. i also tried to export a section, but the “Export” menu is not active.could anyone advise on how?
Is it possible to initialize local parameters, which have the property RetainsValue set? The first time, that the procedure/function is called, I would like the parameter to be initialized by a certain value. Afterwards, when the procedure/function is called again, I would like the parameter to keep the value from the previous procedure call.If I set Initial data for the parameter, the behaviour of RetainsValue is lost and the parameters is initialized with that value in every call to the procedure.
I find that unit conventions are an effective way to display data in different units. E.g. capacity in #items/day, with accompanying cost €/day, are relevant numbers for location specific KPIs. On a higher level, we can change convention to e.g. #mio Items/year, or mio€/year.However, I don't want to apply the selected convention on all my model identifiers. E.g expressing cost per item as €/item, and not as mio€/mio Item when the yearly convention would be selected.Is there a way to override the conventions in model identifiers, and thus explicitly define what uom to always display?Thanks!
Hi All,For a project we are implementing a user is making changes to a relatively large table. The user has the possibility to store these changes in a database.However, when a user closes his/her browser after having made these changes and forgets to store the changes in the database the changes have to be made all over again. Is there a way to raise a warning when closing the browser? In this case that would refer to a user that has made changes, but has not stored them in the database.I know using a uponleave procedure works when navigating to a different page, however when closing a tab no warning is raised using such a uponleave procedure. Furthermore, I have seen multiple sites raising a warning when closing the tab, so curious to see if this is possible to do in the AIMMS WebUI as well!
Hi community,I have a three-dimensional parameter I would like to import. I know how to import one- and two-dimensional parameters, but do not know how to do this one. The data is stored in excel (I have attachted a snapshot as illustration of the structure of the data), I can extract (with some formulas in excel) the range (AM3:AO32) from which i would like to import the data. I also know the number of products (6), number of locations (5) and number of time periods (3). Can someone help me out with this?
Hi, i found something strange in my MILP model.I read my input from an excel file to fill my parameter. The input looks like this: I retrieve this from Excel by the following lines:And eventually in AIMMS it looks like this:What is so special about this column 7 and 8 that they are moved to the left? What can cause the order of the column to be changed without me noticing? Note: Also in my set DiscountLevel, the order is changed:
Hi.I am working to develop a tool that reads some input data from an access database, solves an optimization problem, and then exports results to an output access database. The data import process worked fine when I was accessing the user interface (UI) in page manager. Then, I created an .aimmspack file for deploying the tool for end-user use. Now, when I run the tool from pack file (end-user UI), I get this error during input data reading (image attached). Could someone please help with this error? Could this error be due to me missing to include something during .aimmspack file creation? I have not included the input access database file while creating the pack file. Referring to the image attached, ‘RPS’ is a group in input access database file. Thanks for your help.
Hello! We used to read csv files using a tool called “FFRead” provided by AIMMS. The tool allow us to merge multiple tables of csv data in the same file — below is the content of such a file:I,Table1,City,PopulationD,Table1,Paris,45D,Table1,Lyon,47I,Table2,Country,PopulationD,Table2,UK,76D,Table2,France,89 As “FFRead” is not actively maintained, we are switching to “DataLink” and “CsvProvider”. Does these new tools provide the possibility to read multi-table csv data? Or we must create a new csv file per table?Thank you;Amritbir Gill
HiI am getting the following error while executing my code in AIMMS.“spreadsheet::RetrieveTable(BCLOAD.xlsx, Load_Base(h,y,a), B3:CM8786, A3:A8786, B1:CM2, Load, 1) unable to get a handle to the workbook: Could not open Excel.”I believe it is happening after some automatic updates on my Microsoft office. Previously it was working fine.I tried to reinstall my office, change my excel file name, or even copied the project folder to my PC from the google drive. None of them resolved the issue.It would be grate if you can help me with this issue.
Hi all, I am new to AIMMS and I was wondering if someone could help me with my model. I would like to maximize profit, fulfill as much demand as possible + keeping a safety stock. Besides reorder quantity is restricted by a maximum order quantity (see Sets, Parameters, Variables and Constraints attached). I linearized min(Demand, E). E = demand fulfilled However, when I introduce the maximum order quantity constraints the model becomes infeasible. Besides, the listing file results in the following messages: CPLEX 12.10 constructed the following irreducible infeasibility set (IIS). The IIS consists of 3 constraints and 4 variables. Stock_definition(B,NL19,p-1) .. [ 9 | 31 | IIS ] - 1 * X(B,NL19,p-1) + 1 * Stock(B,NL19,p-1) = -120320 ; (lhs=0) **** Stock_definition(B,NL33,p-1) .. [ 9 | 43 | IIS ] - 1 * X(B,NL33,p-1) + 1 * Stock(B,NL33,p-1) = -428130 ; (lhs=0) **** OQ_B(p-1) .. [ 9 | 152 | IIS ] + 1 * X(B,GB13,p-1) + 1 * X(B,NL19,p-1) + 1 * X(B,NL30,p
Hi there,I am trying to add stochasticity to a deterministic MIP model and I am receiving the following message:The empty row em.Stochastic([M,L,L,L],(B),(B)) .. 0 <= -39688691.0796 is infeasible, as tolerance the option "Bound_Tolerance" is used with value 1e-08.This constraint is:index= (i,j) - at the error message (B) is i and (B) is j;definition sum((k,t), Flow(k,i ,j ,t)) <= sum((e,t),EmissionProfile(e,t))EmissionProfile is the parameter with the scneario tree and Flow is the stochastic variable. Worth to mention the deterministic model is running with no issues I appreciate any light on this topic or how to debug it.Thanks and best regards,Denis
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