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

  • 662 Topics
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662 Topics
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);

120
Chris Kuip
AIMMSian
6 days ago
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

713
J
6 days ago
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

270
Chris Kuip
AIMMSian
9 days ago
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

110
Patrick
Administrator
1 month ago
B
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!

585
gabiservidone
Administrator
2 months ago
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!

253
Marcel Hunting
AIMMSian
2 months ago
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？

121
gdiepen
AIMMS Champ
2 months ago
E
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.  

403
MarcelRoelofs
AIMMSian
2 months ago
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.  

323
MarcelRoelofs
AIMMSian
3 months ago
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?

291
Mischa
AIMMSian
3 months ago
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?

423
R
3 months ago
S
ssamsatliExplorer
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?

161
Chris Kuip
AIMMSian
3 months ago
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.

462
rahmat
3 months ago
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!

484
Wanie Saidi
4 months ago
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?

212
Diego Perez-Urruti
AIMMS Partner
4 months ago
luispinto
Administrator
luispintoCustomer Success Manager
asked in AIMMS Language
Allow end users to make custom formulas

I got a question from @José Fernando Bosch Moreno and I thought it would be interesting to share here.I would like to develop an application for financial projections in which the user can add new parameters that contain formulas based in existing parameters. This is important because generally new calculations have to be developed by information specialist and the time to develop and include new formulations is long. I have developed information systems in which the user can add new calculations and I think AIMMS would be a good alternative to develop financial systems in which the user can add new formulation from the user interface without the need of an information specialist.

161
luispinto
Administrator
4 months ago
A
AnneEnthusiast
asked in AIMMS Language
Show the infeasibility reason in AIMMS

Show the infeasibility reason as in Excel it will have the command to show that the cell is wrong in red, how to apply the concept in AIMMS as to show that the infeasibility in which part clearly. Also to get suggestions from AIMMS on what needs to be changed by what.

261
luispinto
Administrator
4 months ago
Chris Kuip
AIMMSian
Chris KuipAIMMSian
posted in AIMMS Language
Turning sparse data to list format

 equivalent sparse data and list dataToday I got a question to turn a sparse table into a row of lists, as illustrated above.As you can see, the data is the same, just presented differently.To transform the left representation to the right, it helps to work with an indexed set: A list has positions 1 up to max size of the list; which is no more than there are columns:With that we can declare the essence of the list structure as:There are two ways to fill the data, first a more explicit one:As you can see, this requires two references to the indexed set, the first one to limit the elements visited, and the second one to get the position of i_col within the indexed set.By binding the index i_col not to the set s_cols, but directly to the indexed set is_colElems(i_row), the transformation becomes more compact.Once the essence is constructed, we can copy the values, and create a string parameter to present the data actually in list format:  

230
Chris Kuip
AIMMSian
5 months ago
R
rabah.ismaenExplorer
asked in AIMMS Language
Objective function VS CPU time

Hi every oneI would like to implement a cost function VS CPU time curve similarly to the following figure. How we can do it?thanks for your support 

271
gabiservidone
Administrator
5 months ago
N
NajwaFarhanaExplorer
asked in AIMMS Language
Error: PrintStartReport

When a ‘print’ button is pressed, an error message pops up as shown below: Code under the procedure as shown: PR_Verify_PDF_Printer;PrintStartReport(sp_WeeklyReport_Cover_Title);! Print coverPrintPage("r::Weekly Report Cover");! Print summaryPrintPage("r::Weekly Report Summary");for i_WeeklyReport_PrintableMonth do    ! Set month    ep_WeeklyReport_Month := i_WeeklyReport_PrintableMonth;    ! Generate report    pr_WeeklyReport_GenerateReport;    for i_Report_PrintableAffiliate do        ! Set affiliate        ep_WeeklyReport_Affiliate := i_Report_PrintableAffiliate;        ! Generate Affiliate report        pr_WeeklyReport_GenerateAffiliateReport;        ! Print page        PrintPage("r::Weekly Report");        if p_WeeklyReport_PrintExtraGraphs then            ! Print page 2            PrintPage("r::Weekly Report 2");        endif;    endfor;    ! Print monthly totals page    PrintPage("r::Weekly Report Month Total");    pr_WeeklyReport_ClearTotals;endfor;PrintEndReport(); What might

91
gabiservidone
Administrator
5 months ago
Chris Kuip
AIMMSian
Chris KuipAIMMSian
posted in AIMMS Language
The unit and shadowprice of a constraint

Today I got a question on support whether the unit of a constraint influences the shadowprice; for instance, what is the consequence of using [ton] instead of [kg] on the unit of constraint for the shadowprice.A small example illustrates the effects: Variable x {    Range: free;    Unit: kg;}Constraint limX {    Unit: ton;    Property: ShadowPrice;    Definition: x <= 5[kg];}Variable o {    Range: free;    Unit: kg;    Definition: x;}  The base unit of Mass is kg. Running the model, the shadowprice returned for limX was 1; indicating that increasing the rhs by 1 unit (kg), will increase the objective by 1. Then I changed the unit of limX to ton, and solved the model again.The shadowprice returned was 1000; indicating that increasing the rhs by1 unit (ton), increased the objective by 1000. See also: https://documentation.aimms.com/language-reference/optimization-modeling-components/variable-and-constraint-declaration/constraint-declaration-and-attributes.html#constraint-levels-bounds

160
Chris Kuip
AIMMSian
5 months ago
O
OpowiadanicaExplorer
asked in AIMMS Language
Problem with seeing results

Hi,I have a problem with seeing detailed results in my AIMMS program. There are no errors and I get the result for the total cost minimization, but I cannot see any detailed data. Can anyone help me with that? Link to Google Drive with data and program:https://drive.google.com/drive/folders/1QvAuq8sTMautsUEm-3i42Si_1ObSICBe?usp=sharing

472
Marcel Hunting
AIMMSian
5 months ago
C
ChunyangEnthusiast
asked in AIMMS Language
wrong rank in Set element

I use AXLL::ReadSet to read the set element from Excel:And in excel the rank is  However, the data in the set looks like this (the data is in a wrong ranking):Sometimes, it ranks like this:Even though I define the elements directly:Still, the data looks like this:I have ever encountered this problem before, and I was told to define the set as a subset of Integers and use Order by. However, I hope the data in the set is treated as element rather than value. So for a set Time := {1,3,5}, Time(1+1) := 3.What wrong with this?

363
Chris Kuip
AIMMSian
6 months ago
R
RwitamJEnthusiast
posted in AIMMS Language
Storing data iteratively in a parameter

I am trying to develop a model and store the output iteratively. The code I have written is given below. I am trying to store the output “poFGAllocation(sr,d,p,b,f,n,a,s,l)” iteratively. Model is running and showing optimal solution. However, the output parameter returns empty dataframe. pLoopCount is a parameter with initial value 1. while (pCardFG > 0) do for sr do pr_Read_Input_Data; solve mpMaximizeWagonCap where MIP_absolute_optimality_tolerance = 0.05; showProgressWindow(); !vFGAllocationTonsLoop1(xy,sr,d,p,b,f,n,a,s,l) := vFGAllocationTonsLoop(sr,d,p,b,f,n,a,s,l); poFGAllocation(sr,d,p,b,f,n,a,s,l) := vFGAllocationTons(d,p,b,f,n,a,s,l); sFGLoaded := sFGLoaded + {f| sum[(d,p,b,n,a,s,l),vFGAllocationTons(d,p,b,f,n,a,s,l)] >= 0.99}; sFG_ID := sFG_ID - {f| sum[(d,p,b,n,a,s,l),vFGAllocationTons(d,p,b,f,n,a,s,l)] >= 0.95}; endfor; pr_Write_Output_Data; execute("cmd.exe /k 1interProcessData.bat", wait: 1, minimized:1); pLoopCount += 1; endwhile;Kindly help if I am doin

202
gdiepen
AIMMS Champ
6 months ago
Chris Kuip
AIMMSian
Chris KuipAIMMSian
posted in AIMMS Language
Using Identifier selections for control case content

Storing data in so-called cases is the proprietary way of AIMMS to store snapshots of data.For instance, to limit the size, but also to permit loading data for just a selection of identifiers, so-called Case Content Types can be used. Consider a simple application, having scalar parameters a, b, c, and d.  c is the only defined parameter and has definition a * b.Filling in 3,4, and 5 for a, b, and d respectively results in the following screen shot:  With the WebUI data manager, and as Case Content Type: { a, b }, we can save the case.  And this will just store the data of parameters ab, in case ab.data: Now closing the app, and restarting it, we can load this case again.  This will result in the following screen shot: Note:The parameters a and b got their values, because they were stored in the case. The parameter c got its value, because it is a defined parameter. The parameter d did not get a value; it was excluded from the case content type. The following annotated code shows how t

300
Chris Kuip
AIMMSian
6 months ago
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