AIMMS Developer

Topics about getting started or leveling up as an AIMMS developer. Datalinks, AIMMS language, building apps...

  • 618 Topics
  • 1,349 Replies

618 Topics

rahmat
rahmatAce
asked in AIMMS Developer

LP Problems with Uncertain Parameters

Dear All,I have a linear programming problem (from a book of optimization in power system) with uncertain parameters as:max z = 750x1 + 1000x2subject to:x1 + x2 <= ax1 + 2x2 <= b4x1 + 3x2 <= cx1,x2 >= 0where a, b, and c are uncertain parameters with the probability function as:How to implement this optimization problem in AIMMS?Thank you.

0
rahmat
4 days ago
J
juandelExplorer
asked in AIMMS Developer

Gantt Chart

How can you make a Gantt chart based on a binary variable under page manager?

1
gdiepen
AIMMS Champ
4 days ago
C
ChunyangEnthusiast
asked in AIMMS Developer

How to define a complex variable

Hi, is it possible to define a complex variable in AIMMS?

0
C
7 days ago
gdiepen
AIMMS Champ
gdiepenAIMMS Champ
asked in AIMMS Developer

StringToMoment giving weird result

When using the StringToMoment function to calculate the number of hours between two dates and running into something weird: As you can see AIMMS tells me 0 minutes elapsed between 10:00:00 and 11:00:00 My guess is that somehow AIMMS is assuming the referencedate as UTC time, while it assumes the second date as my local timezone.I have also tried to use StringToMoment("%c%y-%m-%d %H:%M:%S %TZ", [minute], "2023-10-11 10:00:00" , "2023-10-11 11:00:00 UTC")To indicate I really want to have the second timestamp as UTC, but that did not help. What is the small/obvious thing I am overlooking here?

3
M
AIMMSian
7 days ago
C
ChunyangEnthusiast
asked in AIMMS Developer

Is it possible to define a inequality function

There is an original expression:W = xyW, x, y are all variables.Now I want to define a function which relax the product of two variables into two inequations:f(AB)={AB* >= A+cB; AB*<= dA+eB} (A,B are input variables and c,d,e are parameters)After defining the function, I want to write the primal expression to:W = f(xy).So the W can be relaxed into two inequations by AIMMS automatically.Is it possible to achive this purpose in AIMMS? Or I need to do the function manually and input the inequations on my own?

0
C
10 days ago
gdiepen
AIMMS Champ
gdiepenAIMMS Champ
asked in AIMMS Developer

Question about index scope not being specified

Hi all, I am aware that AIMMS will use all of the indices specified on the Left Hand Side of an assignment statement to loop over all combinations.When trying out something in a test project I am working on, I wanted to use this logic, but found that this does not work anymore when you are using formatstring on the LHS. Was wondering if this is on purpose or whether this behavior should be possible Example that works:spStringParameter( StringToElement(sTargetSet, iSource, 1) ) := formatstring("Test :: element %e", iSource) ;  Example that does not work:spStringParameter( StringToElement(sTargetSet, formatstring("%e", iSource), 1) :=  formatstring("Test :: element %e", iSource) ;  When running the second one, I get an error indicating that the scope of iSource has not been specified. The above is a minimal example of the problem, not completely the same as what I had. I can work around it by either putting the statement in an explicit for-loop, or create the mapping isource → itarget in

0
gdiepen
AIMMS Champ
10 days ago
gdiepen
AIMMS Champ
gdiepenAIMMS Champ
asked in AIMMS Developer

Question about openapi client generation

Let me first start with one remark: The openAPI client generation is one awesome addition!!! 😀With a bit of a simple workaround I was able to create relatively easy an AIMMS library that was able to import a rather large and complex JSON file that had a quite deep nested structure in it.Now that I have the data in an AIMMS library, I know am trying to write the code that parses the information from the library into the actual AIMMS sets/parameters that I will use in a model.For this part, one of the problems of the nesting is that the generated library works on lots of subsets of integers that restart counting from 0 every time In the following example (that hopefully illustrates it enough)Locations property (contains list of locations):Element 1 in locations list (will map to i_locations=1 in aimms library) LocationName: Location A Products   (contains list of products) Element 1 in productions list  (contains dictionary of name/color, maps to locations::product::i_product=1 in aim

3
gdiepen
AIMMS Champ
9 days ago
M
Marit_vHoutExplorer
asked in AIMMS Developer

AIMMS 4.97 warning in predeclared procedure

Dear AIMMS, I get the following warning about a predeclared procedure when opening AIMMS 4.97 "Warning: The 'queryMap' argument has a dimension mismatch. This will be treated as an error in a future AIMMS versions. Perhaps the argument should be declared as a Handle.”How can this be solved? Regards, Marit

2
M
22 days ago
I
iekeschraderExplorer
asked in AIMMS Developer

Understanding program and solver status

Goodafternoon, In the figure below the result of a solver session is given. Is their a way to figure out what the program status and solver status imply? I used the CPLEX for solving the model.If more information is needed, don't hesitate to contact me.Kind regards,Ieke Schrader Progress window     

1
T
AIMMSian
28 days ago
E
ElineOoms
posted in AIMMS Developer

solving intermediate non-optimal

 Hi, Our model exists of 7 optimizations. However, after the 6th optimization it says that it is terminated by the solver, and it ended up in intermediate non-optimal. What does this mean? Did it end up in a local minimum? Or does it mean something else. Can the results be trusted? If not, how can I solve this? Thanks in advance! 

5
E
27 days ago
R
RwitamJExplorer
asked in AIMMS Developer

AIMMS Encountered a Problem

Dear Team, I am getting the following error while I am trying to run the cutting stock model in AIMMS. My input data size is large.   

1
Marcel Hunting
AIMMSian
2 months ago
M
AIMMS Partner
Marc WingenderAIMMS Partner
asked in AIMMS Developer

data adjustment that invoke multiple uponchanges

Does AIMMS store the information after an user triggers multiple upon change procedures.For example, 2 parameters are in a UI table and an user uses block editing to change both parameter , both wiht their own upon change procedure.Can you know as a developer during the first one that called that also a second will be called later.(i know the order depends on the model tree)

1
luispinto
Administrator
2 months ago
E
EddyEnthusiast
asked in AIMMS Developer

Summation over two sets

Hi All,can someone explain how to enter this as a constraint in AIMMS:(“für alle” means for all)This is what I did:I always get an error notification :(Thanks in advance! Best,Eddy

2
E
2 months ago
E
EddyEnthusiast
posted in AIMMS Developer

How to include a binary variable in GMP::Column::SetAsMultiObjective ?

Hi All,I hope you are doing well! I have a question:I am programming a model with 3 objective functions. The goal is to find the best locations for production.I have diffrect sources, one destination and 4 products.All the objective functions are linear and I used GMP::Column::SetAsMultiObjective to solve them similar. The first function minimizes the costs (price * X(decision variable) + transportation cost * X)The second one minimizes the produced CO2 (CO2 in production * X + CO2 during transport * X)In the last one I want to maximize the social benefit, therefore I wanted to use a binary variable, so if X at a source location is > 0 the binary Variable Y should be 1 (0 otherwise).so the objctive function should be: (Number of created Jobs + other social aspects) * Y This is what I got so far: When I add Y to v_objectiveFunktionSocial the error appears that multi objectives are only for linear models.Is there a way to work with a binary variable here? Or mybe someone has an idea h

5
Marcel Hunting
AIMMSian
2 months ago
R
rmateusEnthusiast
asked in AIMMS Developer

Writing Program and Solver Status using Dex: values rather than labels

While writing the suffices ProgramStatus and SolverStatus from a MathematicalProgram identifier to an Excel file using DEX I get numeric values rather than the lables indicated in this table:https://documentation.aimms.com/language-reference/optimization-modeling-components/solving-mathematical-programs/suffices-and-callbacks.html#table-mp-status Is there any way to write these labels rather than the corresponding numeric values?Otherwise, where could I find the corresponding mapping between the numeric values and the labels (status) referred in the previous table?

3
gdiepen
AIMMS Champ
3 months ago
R
rmateusEnthusiast
asked in AIMMS Developer

Writing ad hoc text to a file using DEX (or AXLL)

Is it possible to write ad hoc text to an Excel file using DEX? How? Otherwise, is it possible to write it using AXLL? How? Thank you

3
gdiepen
AIMMS Champ
3 months ago
rahmat
rahmatAce
asked in AIMMS Developer

Unable to open a project in OneDrive folder

Dear all,I have a problem to open a project that is located in OneDrive folder. But, when I move the project in Google Drive folder, the project is correctly loaded.Is there any setting in AIMMS of OneDrive to solve this issue?Thank you very much.

2
Chris Kuip
AIMMSian
3 months ago
N
NataliaAntunessExplorer
asked in AIMMS Developer

Question about dex

 Hello,I would like to know if it is possible to start reading files from a certain line when importing an .xlsx file using the dex library. And how could this be done?I have a file that contains four header lines and I would like to perform the import ignoring those lines.Thanks 

1
M
AIMMSian
3 months ago
J
JoostEnthusiast
asked in AIMMS Developer

Question on status of a few topics for WebUI

Hi all,I’ve seen here and there some things mentioned on the following items below, but I lost track on the latest developments. Can someone share a status update on them?Have the capability to specify file decimals per identifier (instead of per widget) ? Support for unit (parameters) in WebUI ? Library support for WebUI , i.e. that some WebUI parts / pages become shareable across different AIMMS apps Visible/hidden option per identifier in widget settingsDepending on this I might post an improvement idea for the backlog.Thanks,Joost 

2
J
3 months ago
R
rmateusEnthusiast
asked in AIMMS Developer

"binds-existing" attribute from DEX Library Excel

 The binds-existing attribute can be used in conjunction with the binds-to attribute to indicate that, when reading a data file, no new set elements will be created, allowing for a filtering mechanism where a data file can only be partially read for the nodes that correspond to existing set elements in the model.I have a predefined set named t with valued {1,2,3,4}.I want to read an Excel file which contains a column named “time” having values (e.g., 0, 5, 6) not included in the previous set, which I do not want to add to set t.I am specifying the binds-existing attribute in the DEX mapping as follows:<ColumnMapping name=”time" binds-existing="t" binds-to="t" />I have not changed the skip-non-existing attribute, so I was expecting that binds-existing attribute would not add the referred values (0, 5, 6) into the predefined set t. However, it still does.What am I doing wrong? Did I correctly specify the binds-existing attribute?Thank you very much PS: There are almost no specific

3
J
3 months ago
Chris Kuip
AIMMSian
Chris KuipAIMMSian
posted in AIMMS Developer

Get elements of a set using set name as a string?

Today I got the question: Get elements of a set using set name as a string?This can be achieved using a runtime library.The interface to the data is a procedure with:- input   : the set name- outputs :   o an integer set with the same number of elements  o a string parameter indexed over that integer set with the names of the elements as strings.The tricky part of creating the runtime library is the passing of arguments. Arguments are local identifiers in a procedure, and local identifiers cannot be directly createdusing model editing procedures. This is circumvented by first creating the declaration section, andthen moving that declaration section as a section inside the procedure.An example project which does just that is enclosed.

0
Chris Kuip
AIMMSian
3 months ago
D
AIMMS Partner
David.RichmondAIMMS Partner
asked in AIMMS Developer

Is it possible to bind multiple indices to single column using DEX library?

Given the example of the data I would like to bind each sales volume to a period and sales channel to fill the following parameters . P_MinVolumeSalesChannel(i_Product,i_DemandTerminal,i_Period,iSalesChannel). P_MaxVolumeSalesChannel(i_Product,i_DemandTerminal,i_Period,iSalesChannel).  I know that I could use name-binds-to =”i_Period” and the name-regex-prefix, but could I use name-binds-to again for “i_SalesChannel”?

1
S
AIMMSian
3 months ago
Chris Kuip
AIMMSian
Chris KuipAIMMSian
posted in AIMMS Developer

Develop, Test, and Deploy an AIMMS Service

As you know, the AIMMS PRO REST API can be used to leverage the power of AIMMS applications in other applications.  But how are the AIMMS applications that provide services developed, tested, and deployed?In this short series of small articles, based on a Hello World type of application, it is explained how to develop, test, and deploy an AIMMS app. In addition, it is illustrated how to test this app using clients in other application languages.

0
Chris Kuip
AIMMSian
3 months ago
R
rmateusEnthusiast
asked in AIMMS Developer

Reading zero values using DEX Library Excel

I want to map data from an Excel file using DEX ExcelSheetMapping to a parameter named “Capacity”.However, I cannot get that null (“0”) values are read into the parameter “Capacity”.I have a constraint that imposes an upper limit over a variable named Stock, as follows:Stock <= CapacityI need to read null (“0”) values to impose that the variable Stock is null.How can I do it?Thank you PS: I omit indexes for the sake of simplicity

2
M
AIMMSian
3 months ago
MattC
MattCEnthusiast
asked in AIMMS Developer

DEX OAuth2 Google Service Account

Hello all, I am working to use the OAuth2 flow for the DEX library with a Google service account. Rather than allowing the user to make calls, we would like an OnPrem server to make the call to the Google API. However, Google does not provide a client secret for the Client Credentials flow. Rather, the provide a private key id, private key secret, and client ID (but only for certain scopes). How do I use this in the DEX library to communicate in this way? I don’t see anything that allows this behavior. -Matt

1
RoxannaBindenga
AIMMSian
3 months ago
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