AIMMS Language

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

664 Topics
1,455 Replies

djdmlwnsEnthusiast

asked in AIMMS Language

IPOPT solver is not called

Hello,I am using IPOPT 3.11 solver in AIMMS version 4.87. I tried to solve a Nonlinear model using IPOPT solver, but it shows the message below in the progress windows and does nothing. Any clue on this issue or potential solution?Thank you very much in advance.

RwitamJEnthusiast

asked in AIMMS Language

Data fetching through bigquery using AIMMS

Hi,How to fetch data in AIMMS from a google cloud platform (GCP) database.There is a .JSON file with me along with the queries.

jzomerAIMMS Partner

asked in AIMMS Language

Reset all manually set options

In our project we set options manually. For example, we have lines of code like ‘option CPLEX_22_1.integrality := 1e-05;’. For a specific case that we have, we would like set all these options to their default values and run the case again. What procedure can we use for this?Two things we tried that did not work:We cannot just remove all lines of code where we manually set options, since the case that we have problems with has been run before; hence, the default options in this case have already been overridden. We also tried using the procedure ‘OptionGetValue’ to get the default value and set every option to its default value, but this does not work for the majority of our options. For example, when applying our procedure to the option ‘Advanced_Start’ we get the error ‘Option not found, or not a numeric option’. Another example is the option ‘CPLEX_22_1.integrality’; in that case we get the error ‘The option “CPLEX_22_1.integrality” has not been found’.Thank you!

gekepExplorer

asked in AIMMS Language

Stuck on level 1a G-AIMMS

Hi everybody,I am new to AIMMS and just started the AIMMS Learning Game (G-AIMMS) on the tutorial site (https://how-to.aimms.com/Articles/363/363-getting-started-tutorials.html). However, I am stuck on level 1a (Gathering Ingredients), specifically at the part where I have to add the restriction that at most two markets can be visited. Can anybody help me or does anybody have the solution code?

Noob9000Enthusiast

asked in AIMMS Language

Looping Execution Array

Hello,I'm trying to do some sensitivity runs where I scale a parameter each run and resolve.The problem is I can't seem to very simply make an array to loop over to scale the parameter. Basically this:FOR x in [50, 75, 100] DO y = x * z; solve LP;ENDFOR Just creating the array and looping through it is giving me trouble. I don't know the best way - import the array as a parameter? Then it gets mad it doesn't have an index? But it doesn't even really have an index. Then x has to be a declared parameter as well?Is there an easy way to do this or maybe it's because AIMMS isn't made for scripts? I can't seem to find a syntax guide that talks about declaring an array parameter.Thanks for helping a noob!

LennartEnthusiast

asked in AIMMS Language

What is the .DeveloperState file and how should it be managed with git?

Hi everyone, In the project folder of the model I'm working with, there is a binary file called Main.DeveloperState. I have looked through the documentation but I can find no information on what this file is and does exactly, except that is somehow related to pivot tables. We use and run the model through AIMMS itself, using pages. The DeveloperState file is modified occasionally, but again: it not clear to me what causes these modifications, or what they represent. We work with multiple developers and use git for version control. Because the file is binary, it is not clear how it should be merged (if at all). My questions:What is the purpose of this file? What happens if you delete the file? How to best treat it in git? Can it be ignored? Thanks in advance!

asked in AIMMS Language

AXLL Library: Keeping Workbook Open for Multiple Procedures

Hello all!I am working with a large Excel file that is used across multiple procedures. Loading/opening the Excel file into memory using axll::OpenWorkbook takes a very long time as a result of its size (think almost a minute long), and if at all possible, I would like to keep it open even after one procedure is done running such that the next procedure does not need to spend the time re-opening the workbook again.My observation is that AIMMS automatically closes a workbook once a procedure is done running. Is there a way/option somewhere to keep the book loaded into memory? It would save our users quite a bit of time!Thank you in advance!

rdnExplorer

posted in AIMMS Language

Modelling an if-then "level-up" behavior

Dear AIMMS-community,first, I’d like to thank you for the great software. I think AIMMS is great. About the problem. It's probably easy for the experts among you to solve. So far, I haven't found the right solution. I am developing a model to analyze cost efficient pathways for the ramp-up of production plants for renewable fuels over several periods (t). I consider different plant generations (g), where a lant of a newer generation has "better" characteristics than the ones of the older generation.The addition of plants into the system is defined by a free variable "PLANT_COMMISSIONING(t,g)". Based on this, the overall plant infrastructure is defined with various other variables and constraints. I would now like to integrate the "behaviour" that a new plant generation can only be built if plants of the previous generation have been built beforehand (upscaling), e.g. if a minimum number of plants of the previous generation have been built beforehand. I am looking for an MIP approach fo

RwitamJEnthusiast

asked in AIMMS Language

Oracle DB connection in AIMMS issues

Hi,I am facing some issues while trying to fetch the data through a Oracle DB. I have written the connection string as“"Driver={Oracle in OraClient12home1};Dbq=*****:PORT/*******;Uid=*******;Pwd=*******;"It is showing the following error in database procedure"Read_IO_fines" failed: Error opening datasource ‘Driver={Oracle in OraClient12home1} Dbq=*****:PORT/*******;Uid=*******;Pwd=*******;’, ODBC Error: IM002 [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified.” Am I missing anything. I have Oracle Client installed in my laptop.

Zsolt MihályAIMMS Partner

asked in AIMMS Language

How to check if MP solution is unique?

Is there a parameter that shows if the solution is unique when using CPLEX?

SandipPatelExplorer

posted in AIMMS Language

Opening AIMMS 4.37 project in AIMMS 4.88 crashes the programs

I am trying to open a project that was written in AIMMS 4.37 with AIMMS 4.88. Upon opening it, the window shows ‘compiling’ at the bottom for a few seconds before crashing and closing down. Is this to be expected?Is AIMMS 4.88 compatible with projects written in older versions?Should I expect to see an error message instead of the whole program crashing? Any help would be much appreciated! Thanks,, Sandip

Sajad.KarimiExplorer

asked in AIMMS Language

DEX read JSON file

Hello AIMMS community, I am trying to create a mapping file to read a JSON file using Data Exchange Library. The JSON file is structured as follows:Data: {"CaseTable": [ { "Case": 1, "Specification": "Specification 1" }, { "Case": 2, "Specification": "Specification 2" }]’ "PriceTable": [ { "Contract": "X", "Specification": "Specification 1", "Price": 100 }, { "Contract": "X", "Specification": "Specification 2", "Price": 200 }]}As can be seen, the JSON file includes two tables: "CaseTable" and "PriceTable". I want to read price from PriceTable and assign it to the Price_Parameter(i_case, i_contract) which is indexed over “Case” and “Contract”. For example the value of this parameter should be 200 if the Case 2 and Contract “X” is selected:Price_Parameter(2, X)=200. Case 2 is related to the Specification 2 (according to the CaseTable) and the price

jzomerAIMMS Partner

asked in AIMMS Language

Finding the first element of a multi-indexed parameter

I have a multi-indexed parameter, say pMatrix(i,j). I want to efficiently get the first element of the matrix.Applying the First-operator (i.e. First((i,j) | pMatrix(i,j))) did not work; it results in the following error: “The iterative operator first can have only one iterative index.”I can think of some workarounds (such as to start by finding the first i, and given this i finding the first j), but this is quite cumbersome, especially when there are more than two indices (in our project we sometimes have up to 7 indices).How should this be elegantly addressed?

PatrickAdministrator

posted in AIMMS Language

Test Driven Development using the AIMMSUnitTest Library

This article discusses some elements from the popular software methodology Test Driven Development in relation to the AIMMS Library AIMMSUnitTest. Gather requirements from stakeholders What are small examples? What are the edge cases, including error cases, performance? Implement requirements as unit tests and see them fail! Development Write the code for the functions Execute tests and see them pass! Refactor until performance is acceptable. Repeat Read more...

sara62Explorer

asked in AIMMS Language

Running multiple instances and the data manager tool

In the new version of aimms, the “data manager button” does not exist. I used to run multiple instances as a batch file using the data manager. I saw the “select multiple case files option” but I could not figure out how to use itto run a set of instances automatically. I appreciate any help in advance.

Chris KuipAIMMSian

published in AIMMS Language

ProfilerRunCompare App

Existing successful applications often have several features. To realize all these features there is a significant body of code.An application developer may be faced by a small change that causes significant differences in runtimes.Examples of such small changes are:a change in data, a code hotfix, a switch of computing environment, or two different persons operating the application.The location of the code where these performance differences manifest themselves may not be obvious. Facilitating the adage: measuring is knowing: the AIMMS engine provides the diagnostic tool: AIMMS Profiler.The AIMMS application ProfilerRunCompare is a small tool to compare two profiler runs. Come and check it out here.

Noob9000Enthusiast

asked in AIMMS Language

Write a Slice to a Composite Table

Hey! I'm trying to export using AXLL and have been able to write single variables and simple composite tables, but can't figure out how to slice a variable. I'm not sure if this is something I haven't learned about Sets or something with WriteCompositeTable.I want to do this:my_set := {A(x, ‘Blue’), B(x)}axll::WriteCompositeTable( IdentifierReference : my_set, TopLeftCell : "A1");It's the ‘Blue’ part that I can't figure out.Thanks in advance!

ndmileEnthusiast

asked in AIMMS Language

Write into excel from multiply parameters and variables

Hello,I have a question related to writing a result to excel. I know how to write a matrix from a single parameter to excel, however I have trouble constructing a single table where all values match. If I have a parameter location(city, xy), where city is a set’s list, while xy has two columns (latitude, longitude), and I would like to combine with parameter Client(city,client), and parameter DistanceClient(city, distance), and parameter ClientDemand(client, poroductdemand), how do I save this data into one table where the rows and columns match?NOTE: each city has different number of clients: city1 has 4 clients, while, city2 has 8 clients, etc.How to obtained the following matrix in excel that looks like this: latitude longitude client distance productdemand city1city2city3….cityn I’m really appreciate your help :)Kind regards

melody.shellmanAIMMS Partner

asked in AIMMS Language

DEX read Excel/CSV Parent and Child table

Hello AIMMS Community!I’m looking to understand if it’s possible for AIMMS Data Exchange Library to read an excel file that is structured something like this (modified from the sample on the DEL documentation for EXCEL):In this structure, we have an excel sheet called “Table1”. The table on this sheet has two columns that map to an index (set1 [i], set2 [j]), two parameters that are defined over these indices (d1, d2, d3) and a child table that uses the two defined indices and a third index for time that maps to a parameter p_test(i,j,k) . Where k is defined by set in columns (Time-1, time-2, time-3). I’ve been able to successfully read d1 and d2, but I’m having trouble understanding if it’s possible to read a third index in the column. The current documentation does not describe thisThe motivation for using DEX in this case is that we have have existing XML files that read the same data from JSON (output from database calls). We’d like to leverage these XML files to create excel mapp

LisaExplorer

posted in AIMMS Language

Inventory Routing Problem in AIMMS

Dear AIMMS community group,I’m currently working on modelling an Inventory Routing Problem in AIMMS based on below model formulation to minimize the total transportation and inventory cost.I have created a project in AIMMS as enclosed, however despite no errors I don’t receive a solution (solution is total cost of 0).Therefore, hoping someone can support to have a look at my model and advise on what might be wrong and how to solve to generate the solution.I’m attaching you my AIMMS project as well as the model formulation that I’m using.Thanks a lot in advance!

ndmileEnthusiast

asked in AIMMS Language

Combine table data into one line

Hi everbody,I want to generate an integer parameter that contain whole data from the table in one line, where the values for the same row are sparated by “,” and values of each rows are separated by “|”.Wish the final result looks like that:“1, 2 | 3, 4 | 5, 5 | 6, 7 | 8, 9 | 12, 0”Table:Location\XY Lan Long Place1 1 2 Place 2 3 4 Place 3 5 5 Place 4 6 7 Place 5 8 9 Place 6 12 0 The data is located in the parameter(cityID, XY). Where CityID corresponds to list of cities, and XY has two possible values “Lan” and “Long”.Thank you for your help :)Cheers,

DuMiExplorer

asked in AIMMS Language

Gantt Chart Newbie Question

Hello,I have a problem with Aimms, I tried to program a Gantt Chart and a Calendar. For excercise I followed the Demos. So my question is after I wrote the program where can I see the Calendar or the Gantt Chart ?Do I have to use the widget or install some other extension ? Thx for your help

bedelilllaAIMMS Partner

asked in AIMMS Language

Data Exchange write out only nondefault values

Hi, Is there any attribute which can ensure that only nondefault values are written to Excel?Like axll:WriteTable function has writeZeros argument and if it is set to 1 then zero cells will remain empty. Thanks,Lilla

asked in AIMMS Language

Discrete Uniform Distribution

Hello everyone, Is there a way to use a discrete uniform distribution inside of Aimms? I know there is a uniform distribution but it gives me real number values for my parameter. Instead i just want integer values to be drawn from the uniform distribution. Is this possible? Thank you for an answer. Kind regardsAlex

AndrewTExplorer

asked in AIMMS Language

Check if an element parameter has a value

Hello everyone, I have an Element Parameter PredecessorOperations(i_operation) that holds the value of the operation that has to be executed before i_operation. With the following statement i want to check if the EP has a value or not: if (val(PredeccesorOperation(i_operation)) = 0) then….endif; However this only works if all values of the Ep are empty. If any operation gets assigned a predeccesor (e.g. Operation1) then i get the error: Cannot compute the value of string “Operation1”. If I would casually formulate the code it would look like this: if( PredeccesorOperation(i_operation) is empty ) then ….endif;So my question is: What operator do I need to use in order to check if the parameter has any value or no value assigned? I am thankful for any advice you might have. With kind regardsAndrew

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