AIMMS Language

Hi,I want to be able to write some specific messages into AIMMS Pro Session Log file from inside AIMMS.How can I do that?Best,Gorkem

Hi,Here is the set that I have and is a subset of AllVariables with the index i_DistWeightVar. Note that the variables in this set have exactly the same indices and in the same order, (i.e., i_period, i_Terminal, i_Source, i_Product, i_Fleet, i_Zone, i_Customer).Here is the parameter that I create that only differs with his first index than the variables in the set above.I am hoping to be able to make assignments by using a function like StringToVariable given below:Anything you can give me to use on the RHS of this assignment?Best,Gorkem

I’d like to thank the great support we received from the AIMMS team and specifically ​@Chris Kuip!For our joint customer DHL Benelux we’ve build an AIMMS tool. Some details on the case:DHL annually ships over 100 million parcels from A to B. These millions of parcels go through 3 stages:First mile: collect the parcel at A and bring it to a sorting center/hub Linehaul transport: bring the parcel from the first sorting center to its destination sorting center (this transport is sometimes called the network) Last mile: deliver the parcel from the destination sorting center to BOur AIMMS based tactical planning optimization tool enables step 2, the network planning: it can automatically create an optimized linehaul planning, considering available resources, crossdocking, sorting curves, special pickups, round trips, one ways, driver breaks and more. One necessary step in the algorithm is to generate new routes. This is in essence a breadth first search variant, and it was the slowest step

Dear all,Is there a probability function in AIMMS?For example, I want to calculate:where:x: The capacity of power plant to be constructed (MW)y: Installed capacity of power plantF: force outage rate of power plant Thank you very much…. 

Hi, Let’s say I have a set consisting of 5 elements such that: Set1 = {‘A’,‘B’,‘C’,‘D’,‘E’}.How can I move some elements to the end of the set. For example:Set1 = {‘A’, ‘D’,’E’,’B’,’C’} Thanks!

Resolved!Thank you!

Hi everyone,On June 11, AIMMS hosted the webinar "Why So Slow?" — a session all about understanding and improving model performance.A big thank you to everyone who joined!It was wonderful to see (and recognize!) so many familiar names from across AIMMS, our clients, and partners. It's always a great reminder of how connected and collaborative our community is.We hope you found the session both insightful and enjoyable — even if we got a little deep into the technical weeds at times. 😅As promised, 📎 slides are attached to this topicIf you have any follow-up questions or thoughts, feel free to post them here. We’d love to keep the conversation going!And if you couldn’t make it — no worries.The recording is available, and even some of our most experienced users told us they picked up a few new insights.▶️ You can view the recording here

Can anyone tell me if there is a way to write profiler output to a file?     An external application is invoking AIMMS from the command line multiple times during its run, so it would be useful to generate this file 

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!

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.

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 ?

 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"

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

 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! 

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. 

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. 

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

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. 

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);

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

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

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

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!

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!

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？