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AIMMS Language

Topics about getting started or leveling up as an AIMMS developer.

  • 672 Topics
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673 Topics
Chris Kuip
AIMMSian
Chris KuipAIMMSian
posted in AIMMS Language
Lane numbering - Execution Efficiency

One of our customers encountered a bottleneck doing lane numbering.Given a binary parameter bp_laneExists( i_locFrom, i_locTo ), can you efficiently number the lanes?The essence of their code looked as follows: 2dim loop over all lanesAs you can see, on my laptop this loop takes ~14 sec.I was able to reduce the dimension by one with the following code:1dim loop assigning outgoing lanes per location.As you can see, on my laptop this loop takes ~1.7 sec.Please find my sample project enclosed.

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Chris Kuip
AIMMSian
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denghaiyingEnthusiast
asked in AIMMS Language
How to send a presolve solution to its original MathematicalProgram?

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 ?

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Marcel Hunting
AIMMSian
D
delta2295Enthusiast
asked in AIMMS Language
Unpack .aimmspack file

 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"

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Chris Kuip
AIMMSian
C
ChunyangEnthusiast
posted in AIMMS Language
Complex value assignment efficiency problem

Hi I am trying to do a value assignment in AIMMS. Here is the example:t and i are both the index of set time. n and r are the index for set Node. NodeInTime, needed_value are predetermined parameters. scenario is parameter changing in the process. noted_scenarios_index is a subset of Node. path is a mapping between index (r,t) and set Node.for (n,t)| t<>first(time) and n<=NodeInTime(t) do   scenario := 1;   noted_scenarios_index := {r | r <= NodeInTime(t) and path(r, t) = n};   for r in noted_scenarios_index do        needed_value(scenario, n, t, i) := value(path(r,i), i);        scenario := scenario + 1;   endfor;endfor;I used debug move to check and surprisingly, the slowest part is:needed_value(scenario, n, t, i) := value(path(r,i), i);when it runs to this line, ‘scenario’, ‘n’, ‘t’ are determined and it took more than 30s to run this line….. So I don’t understand why it’s so slow.I also tried using an additional parameter like:addition(i) := value(path(r,i), i);needed_v

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bestwayyyExplorer
asked in AIMMS Language
exists function with corresponding indices

 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! 

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luispinto
AIMMSian
B
bestwayyyExplorer
asked in AIMMS Language
converting parameter to index

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. 

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gabiservidone
Administrator
Chris Kuip
AIMMSian
Chris KuipAIMMSian
posted in AIMMS Language
Zip lib

Hello AIMMS Community,This post introduces the AIMMS Zip Library, a tool designed to streamline your file management tasks. This library provides functions to zip and unzip folders, making it easier to handle large sets of files efficiently.Key features:Two AIMMS procedures  zip::pr_zipFolderToFile To compress a folder into a file  zip::pr_unzipFileToFolder To expand a file into a folder These procedures provide the same results on Windows and Linux.Workings:On Linux, it is assumed that zip and unzip are installed. On Windows, the Powershell Compress-Archive and Expand-Archive are used.Installation in your application: please use a download links provided in this how-to article.We hope you find use for these commands. 

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Chris Kuip
AIMMSian
rahmat
rahmatAce
asked in AIMMS Language
display multiple variable data in a parameter

Dear AIMMS expert,Is it possible to display several variable data with a single parameter?Thank you very much.

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gdiepen
AIMMS Champ
C
C123Explorer
asked in AIMMS Language
Error message: "abort is not in the set AllIdentifiers".

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!

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ActicorExplorer
asked in AIMMS Language
How to write a constraint with format variable smaller equal to parameter?

Hello, I am a beginner at using AIMMS and have my sets, parameters and variables all sorted out. I am, however, stuck with one constraint. I have a variable x(p) (so x(p) needed) and parameter d(p) (max capacity (p)) and want to have a constraint x(p) <= d(p), but without havin to use a sum. How do I so this? Thank you. 

271
gabiservidone
Administrator
Chris Kuip
AIMMSian
Chris KuipAIMMSian
posted in AIMMS Language
Is this Stream a Volume or a Weight?

One of the most frequently asked questions in the process industry is whether a given stream is measured by volume or weight. With AIMMS, this can be easily determined by examining the unit of measurement (UoM) assigned to the stream. In AIMMS, UoMs are managed as data and stored in what are known as unit parameters.For example, consider three streams: a, b, and c. The units for these streams can be specified in AIMMS as follows:data { a : [kg], b : [ton], c : [m3] }To determine if a stream is a weight, you need to check if its UoM is commensurate with the base unit of weight. Assuming we have a function fnc_isCommensurate(up_a, up_b), you can use the following expression:fnc_isCommensurate(up_strUnit(i_stream), up_baseUnitWeight)This will indicate for each stream whether it is measured by weight.Using the AIMMS intrinsic function AtomicUnit, the fnc_isCommensurate function can be implemented as:fnc_isCommensurate := AtomicUnit(up_a) = AtomicUnit(up_b);

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Chris Kuip
AIMMSian
Chris Kuip
AIMMSian
Chris KuipAIMMSian
posted in AIMMS Language
An illustration of the new AimmsDEX mapping attributes binds-to-display-name and range-display-name.

Machine efficient data sources often identify objects via numbers.  Human friendly representations of same data uses names instead. When exchanging data with both machine efficient data sources and human friendly data sources translations are common.The attributes binds-to-display-name and range-display-name, introduced with AimmsDEX 24.6, facilitate translations between element representations, for instance a translation from number to name and visa versa. InterfaceThe running example uses locations and connections, and its interface looks as follows:The locations are actually numbers, and the annotation webui::ElementTextIdentifiers translates these numbers to names in the UI. InputThe input is in SQLite tables, such as: The input identifies each location by its number, and has a name as attribute​​​​​​ Writing Excel directly: With this data, it can be directly written to an Excel sheet.The mapping file this table looks as follows: And the corresponding data sheet that comes out of i

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Chris Kuip
AIMMSian
Chris KuipAIMMSian
posted in AIMMS Language
Memory reuse

The other day a customer was asking about the statements empty, cleanup, cleandepedents, and rebuild.  In addition, that customer wanted advice on memory management when running multiple data instances for the operations research problem at hand.These two questions will be handled in two subsections below.Quick overview of some data management functions. If S is a set, index i in S, and parameters P(i), Q(i,j) exist,then the statementEmpty S ;will remove all data from S, P, and Q.There is a variant of the Empty statement that operates onsubsets of AllIdentifiers. Let the set sIds, subset of AllIdentifiers, be { P, Q }.Then the statement:Empty sIds ;is implemented as emptying the data of P and Q, not of sIds.Additionally, if S used to be data { a, b }, but is now { b },and P used to have data { a : 1, b : 2 }then:('a':1 ) is called an inactive element of P.To remove the inactive data in P, there are two alternatives:Alternative 1. The statementCleanup P ;will remove the inactive data fr

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Chris Kuip
AIMMSian
Patrick
Administrator
PatrickAdministrator
posted in AIMMS Language
Valorization

This week, our partner CQM published a great use case on "valorization." The article is in Dutch, so I asked ChatGPT to translate it.https://cqm.nl/nl/cases/vips-maakt-planning-vion-datagedreven In agriculture, food production, and food processing industries, "valorization" is crucial. It increases the value, utility, or profitability of a product. In the meat processing industry, this means utilizing every part of the animal as efficiently as possible and making the most out of the meat. It’s a highly complex process with many variables. Together with meat producer Vion, CQM developed the VIPS application, which has made Vion's planning data-driven.Vion Food Group's largest production site is located in Boxtel. Vion is an international producer of meat, meat products, and plant-based alternatives. From this location, fresh meat and processed meat products are supplied to national and international retailers, food service industries, and the meat processing industry. Due to their scale

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Patrick
Administrator
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beatrizcelanteEnthusiast
posted in AIMMS Language
Issues importing a parameter from an empty cell

Hi, everyone! I’m trying to import a parameter based on a excel sheet. The cell is empty and the parameter is set with a default value of inf, but the parameter keep assuming value of zero. There’s anything that I can do to, if the cell is empty, the value assumed be different than zero?I don’t know if this should happen or if it’s an issue that has already been fixed. I’m using the verison 4.85, by the way. Thank you very much!

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gabiservidone
Administrator
J
Jingfan LiuEnthusiast
posted in AIMMS Language
The definition of constraint contains a goniometric function.

I have been trying to construct a optimal power flow(OPF) model. I refer to the OPF model in “How-to”, and add time terms( 24-hour optimisation cycles), energy storage and renewable generation to the model. However, there is an error of “The definition of constraint contains a goniometric function, which cannot be handled by BARON” in my model. This problem did not appear in the original model even though it also has geometric functions.Does anyone know why and how to avoid such errors? Thank you very much!

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Marcel Hunting
AIMMSian
J
Jingfan LiuEnthusiast
asked in AIMMS Language
copy one Section in Project A to Project B

Can AIMMS achieve the function that copy one Section in Project A to Project B?  For example, there are two projects that need to use the energy storage model. I've built an energy storage module in Project A. How can I copy this module to Project B to avoid repetitive modeling？

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gdiepen
AIMMS Champ
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AIMMS Partner
erika.hashigutiAIMMS Partner
asked in AIMMS Language
Importing scalar parameters using dex

I have an excel file with many spreadsheets. Almost all of them have tabular data information. But one of them has information like the image below. I read the documentation I found about dex, but I couldn't find out if it is possible to import using this format and how to do it.  

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MarcelRoelofs
AIMMSian
R
RwitamJEnthusiast
posted in AIMMS Language
Dataframe operation in AIMMS

I am trying to do some dataframe operation through AIMMS. I am giving some sample example. Say, only one row is there in a dataframe. The values are TC130 and SF520. Say the parameter name is ```pMap(tdc1, tdc2)```.  I would like to run a for loop on the second column value, i.e. on tdc2. Here it is SF520, I'll extract the corresponding value of SF520, which is TC130. Now I'll check in another dataframe, where quantity has been given for TC130. The parameter is ```p(tdc1)```.  If TC130 belongs to that dataframe, i.e. if p(tdc1) > 0 then I'll create a parameter on tdc2, say p(tdc2) and assign value 1 to that else 0.How to write this types of procudure in AIMMS. In a nutshell. I have two parameters p(tdc1, tdc2):= {(tdc1, tdc2) : 1} and p(tdc1):= {tdc1: quantity}. This is simple case.  

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MarcelRoelofs
AIMMSian
R
robbEnthusiast
asked in AIMMS Language
How to reference Project Title in code

We have multiple projects and I’d like to use the same code (that i’m writing) for each project. In this code, ideally, it would write the Project Title to the database, along with some other data. How can I access that Project Title via the aimms code?

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Mischa
AIMMSian
sarah rohaizad
sarah rohaizadEnthusiast
posted in AIMMS Language
Difference Between Declaration

parameter Demo_Lab(c,l) is the element of c. So to declare the constraints, I insert this equation at the constraints definition.In this picture, I inserted the parameter in index domain of variables. So, I have question. What’s the differences between these two type of declaration? and what is the condition to use each of it. Can someone explain to me?

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R
S
ssamsatliEnthusiast
asked in AIMMS Language
SetElementRename not working

I am using SetElementRename to rename one of my elements. However, each time I run the function, it claims that the element is specified in the model and cannot be renamed, but this element is not hard-coded in any part of the model.Has anyone actually got this function to work?

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Chris Kuip
AIMMSian
rahmat
rahmatAce
asked in AIMMS Language
Interpolation formula in AIMMS

Dear All,I want to apply an interpolation formula to determine the value of a parameter. For example, a parameter that states the emission limit to achieve a net zero emission system has a value in 2025 of 1000 tons of CO2 and in 2050 the emission target is 0. How do I fill in the emission value between 2025 and 2050?Thank you for the advice given.

492
rahmat
Wanie Saidi
Wanie SaidiEnthusiast
asked in AIMMS Language
Subset & Parameter

Hi,I am currently working on a project using AIMMS, and I have a question regarding the declaration of data as Subsets and Parameters. I understand the basic concepts, but I am a bit confused about the difference between Subsets and Parameters.In my understanding, both Subsets and Parameters seem to serve similar purposes, but I am sure there are distinct differences between them. Could someone please explain the difference between Subsets and Parameters in AIMMA, and provide some examples of when to uses each?Thank you in advance for your help!

764
Wanie Saidi
Diego Perez-Urruti
AIMMS Partner
Diego Perez-UrrutiAIMMS Partner
asked in AIMMS Language
NameChangeFile (nch) size trimming

Hi @AIMMS Community Team, ⁠For one of our bespoke apps the name change file is way larger than it needs to be. Do you know if there's any AIMMS functionality to do a one-time compression/clean-up for a project?

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Diego Perez-Urruti
AIMMS Partner
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