Topics about getting started or leveling up as an AIMMS developer. Datalinks, AIMMS language, building apps...
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Dear All, I want to model the power of wind turbine under different wind speeds with resect to the cut-in, cut-out and rated speeds. How can this be implemented in AIMMS. Please, kindly make your response comprehensive as i am new to AIMMS. Thank you. All the terms have been declared as parameters.
Good day people….i am new to AIMMS. I want AIMMS to read from a dat file but it keeps giving me the statement “The symbol ";" is not expected.” The content of the dat file is COMPOSITE TABLE:G M P R_M R_P!-------------10 8 4 10 15 ; after removing the symbol ; it pops up another error which is ‘The symbol "15 " is not expected.’after removing 15, it pops up another error which is ‘The symbol "10 " is not expected.” Is there something i am not getting right on how to structure the contents in dat file. Kindly help please.
Hello,I’m a student who is using AIMMS for my university project and I am using a academic license.Yesterday i started receiving the error message “Error in AIMMS license - Inconsistent system date” during the solving process.It happens typically while solving my model for some time (around 1 hour)AIMMS gives me the choice between exiting now without saving or exit later with a timer of about one minute to save my project. Has any one encounter this problem and knows a soulution?
Hi, I have a String Parameter with index domain “i” called “ModPrefix” containing prefixes of modules within my project. Each of this modules has a variable with the name “Q”. Now, I would like to access these variables within the definition of a Node called “FacilityNode” likeNetOutflow = ModPrefix(i)::QHowever, this leads to the errorThe identifier "Q" has not been declared, but it is declared in the modules [...].where I replaced the names of the modules with “[...]”. My idea of a workaround was an if-then-else-statement likeNetOutflow = if ( ModPrefix(i) = "prefix1" ) then prefix1:Q elseif ( ModPrefix(i) = "prefix2" ) then prefix2:Q else 0 endif;in the case of two modules with prefixes “prefix1” and “prefix2”. However, I would still like to know if there is a way to circumvent it-then-else-statements, since they become ugly in the case of many modules.
Hello everyone after formulating my model in AIMMS, the solver tells me that my solution is not feasible I tried to simplify my model by removing some binary elements but I still get the same answer. I think the problem must be somewhere in the flow conservation or capacity constraint, could someone take a look at it and tell me the problem.I also have a duplicate column warning message I think it's from my bad formulation of the problem if someone can also tell me how to fix it thank you very much.Ps: I saw that these questions were asked regularly but I took the liberty of making a new topic because I would like to have an answer specific to my case and I could not solve my problem by reading the other topic.
Really excited about this last demo.Please remember, this is a peek into our internal demo's, items can change, be update, removed as they move forward.Parallel solving We had a nice presentation from @Chris Kuip on parallel solving. A combination of several technics: creating job's on cloud, using multithreads, asynchronous solving, updating of matrixes. Will be very useful for case in which you require hundreds, if not thousands, of solves for you problem. Even better if the differences between the solves are very small in the data from one solve to the other. You can expect a how-to and project/library soon with this information. Debugging on error Very nice addition to our debugging functionality. With this new option (still unreleased!), you will be able to start debugging as soon as an error is raised in AIMMS. Excel Tabular data A great step forward on our WebUI tabular data capabilities within AIMMS. This is still a feature spike (interpret as: very initial phases, could poten
I am a student and have been using AIMMS for roughly a year already. When I tried opening AIMMS today, the following occured: Logging on to AIMMS License Server failed: No logon response from server.Another user had the same problem, however the solution to that post didn't work. Did the license expire or is something else the problem?
Hello everyone, this is my error message.Warning: After zero iterations the preprocessor of CPLEX 20.1 concluded that MinCost is infeasible or unbounded.I think the problems lays in my constraints.Production_workcenter is 100% incorrect but i’m not sure how to use the subset allowed_product_per_workcenterAre there other problems ?Thank you Marc
Hi!The model aims to optimize the energy flow in my superstructure and minimize the cost. Most of the data in the listing file show that the status is superbasic and some of them are superbasic, at bound. Here is the message showing on top of the listing file.CONOPT 4.1 constructed the following irreducible infeasibility set (IIS).The IIS consists of 1 constraint and 1 variable.HWH(6) .. [ 9 | 273 | IIS ] + 1 * Techflow(HW,6) - 0.800 * NGflow(HWH,6) = 0 ; (lhs=-25630, scale=3600000) **** name lower level upper scale Techflow(HW,6) -inf -25630 inf 3600000 NGflow(HWH,6) 0 0 inf 3600000 <--- pivot columnThe constraint is stated like this:HWH(t):Techflow('HW',t)=EfficiencyNG('HWH')*NGflow('HWH',t)Attached is the zipped file for my model. I would appreciate if anyone could help me to solve this.
Hello, I’m trying to solve my thesis model but there has been message about infeasible solution. ‘’Warning: After zero iterations CONOPT 4.1 concluded that ModelNew is locally infeasible.’’ I obtained some data in the listing file but the model is still showing infeasible. I would appreciate if anyone could help me to solve the infeasible problem.As attached is the zipped file of my model (Model New.data is the data file of my model).Thank you in advance.
We currently work on using the AIMMS Unit Test Library for all our tests instead of manually checking the success of a test run with the help of binary parameters. In this context, we thought of emptying all parameters before the run of each unit test to ensure that the run sequence of tests does not impact the outcome. We noticed that emptying all identifiers also leads to emptying parameters with initial data. Is there a way to reset all parameters to the state before we ran the unit tests or at least to their initial data? Kind regardsSandra
Hi! I’m doing a supply chain optimization using AIMMS for my master project and I have a problem with my binary determinant variable as well as the result error computed. Since this is my first time using AIMMS, I am not sure on how to debug it.The constraint of my binary is X(i,l,g,g2) + X(i,l,g2,g) ; where g≠g2.After I run the program, it saysWarning: The rows "TransportationBinary(liquid hydrogen,truck,g1,g3)" and "TransportationBinary(liquid hydrogen,truck,g3,g1)" are equal in the generated mathematical program "MinimizeDailyCost". This may lead to non-unique shadow prices. For more information regarding potential causes and consequences, see the help associated with the option "Warning_duplicate_row". Can anyone help me explain what is the problem? I am also confuse on which section to declare the g≠g2 in the transportation constraint (g represents the grid squares/ supply demand location).Appreciate your help!
Hello AIMMS community!I currently working with aimms on my thesis and for my model i need the MainExecution read a huge amount of sets and parameters. For that I’m using Excel-Sheets. I also going to need subsets and here is my, i think, for you, very simple question:How can I exclude Excel cells from being readed? For example one of my sets is readed asSpreadsheet::RetrieveSet ( WorkbookName, facilities, "A4:A75");If now a subset of facilities is not contigious in this column A4:A75 but instead maybe the cells A10 to A15 and A20 to A30 and A50. How would i retrieve this subset? I tried this (see below) and many other variants and nothing worked. Hope you can help me. Spreadsheet::RetrieveSet ( WorkbookName, facilities, "A10:A15+A20:A30+A50");
Hello everyone, In the problem that I have to solve, I have got two sets: j (=1, …, 5) and k (=1, …, 9). I also have a parameter: parameter(j,k) and I want that j begins from 2 (and not from 1) for this parameter. How do I put it in AIMMS? Moreover, in my objective function I want to minimize the sum of my costs but for j >= 2. My current formula looks like this: sum[j, 200*W(j)] with W(j) a variableHow do I specify that I want j to be larger or equal than 2? Thank you
Running late on this one! Even if it was a while back, I think there were interesting things going on. We have been working on a new compilar. We are not done yet (no changes to product as of yet), but progress has been made. When this is done, it opens up possibilities for innovations in the use of the AIMMS language. Combination chart! How this grows! We now allow you to specify an interval for the X-axis label. Nice to clean up label-heavy axis. It is now possible to hide specific indexes from being displayed - which can also make legends and labels less cluttered and more useful. I see two nice use cases: similar to pivoting the identifier label to the totals; hiding auxiliary indexes that shouldn't be shown to end-user. Combination chart on non grid - now you can see that it is incompatible (isn't of just not showing up). Tooltips are now also supported on the Selectionbox, Multiselect and Legend widgets, by using a Tooltip Identifier for the relevant identifier(s) in your mo
In this How-To article we explain how to implement the usage of the data formats (JSON, XML, CSV, Excel, Parquet) in mapping files and, if applicable, format-specific requirements. This article is part of a How-To series on the DEX. Let us know if you have any questions about using the DEX and/or suggestions for follow-up articles! Go to article: Dealing with different data types in the DEXNew to DEX? Start here!
Hi, I’ve been developing some stuffs using webUI. But, somehow, some part of it (what I did earlier) is still there when I refresh the Chrome while the other part of it is gone whenever I refresh or go to the previous page. How to save the pages and interfaces that we have made in webUI ya? I’m using the latest version of AIMMS (AIMMS 126.96.36.199 64-bit).Thanks,Zulfan
Demo time!First off we had a demonstration of the capabilities of Octeract, a global MINLP solver that has been linked to AIMMS. The new options are always great since they can provide alternatives for our clients to pick the best of the breed for each problem. And as such, this solver can be useful for some problems. More on them here:https://octeract.com/ Next was a cool progress update on our Application Management via API Calls. I see great potential for integrating AIMMS in other solution via API's but also integrating CI/CD with this functionality. Finally, @Gertjan shared numbers on the community edition license which is now 1 year old! Check our celebration post here: Share your thoughts!
Our AIMMS Community License has completed it's first year! 🎉🎊🎈And we are very happy in the reception that this free edition got by our users.Looking back at the original post, I love the proposed intentions for this release. To quote @Gloria Quintanilla :Whether it’s crafting a plan to reduce your personal carbon footprint, creating a schedule for your kids’ school or simply to learn and experiment, AIMMS Community Edition is ideal for those who want to apply modeling to improve decision making. It’s also a great companion for recent graduates who previously used an AIMMS Academic License but want to continue playing with the software at no cost, or showcase their AIMMS skills to prospective employers. So, what did the community edition do for you? Please share with us!And if you still don't have a license, jump right on:https://licensing.cloud.aimms.com/license/community.htm?utm_source=website&utm_medium=footer
Waiting for sub jobs to complete For large jobs, it may make sense to split it into multiple jobs. It may not be convenient, or appropriate, to let the client session organize the communication between the various jobs.This article presents and discusses an example, whereby one control job manages several sub jobs. In addition, results are presented in the client session when all jobs are finished. Read more...
Hi, I was trying to play around with Monte Carlo simulation in AIMMS. I can save the results from MP.Objective for every run. But, how can I save the solution for every run? I tried to use something like below for every run:Variable_Result(run, param1, param2) := Variable(param1,param2);It’s in the procedure “RunMonteCarlo” in the attached file. But, it doesn’t work. Any idea?Thanks,Zulfan
Hi, I’ve been trying to run some Monte Carlo simulations, but apparently if the number of runs is more than 500, the Histogram cannot be made. AIMMS returns some arithmetic error that I don’t understand. How can we increase the number of data that Histogram can make?Thanks,Zulfan
Hello everyone,in contrast to other programming languages, the source code of an AIMMS model usually is in a single file. Our code is hosted at a GitLab instance. Our team notices, that GitLab struggles with the large .ams-file, especially in merge requests. Sometimes the diff is too large to be shown, posting comments (as a reviewer as part of a code review) fails, or loading already posted comments fails. The size of our .ams-file is usually between 1 MB and 5 MB.Has anyone else experienced similar issues? Does anyone know a good alternative to conduct code reviews, which does not involve hosting the code on a different platform?I’m aware that we could use libraries to divide the code in smaller chunks, however, I feel like this is not as easy as in other programming languages and not the way it’s “supposed to be” in AIMMS.Best regardsBenedikt
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