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AIMMS Developer

AIMMS Developer

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

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RichardAIMMS Implementation Partner

posted in AIMMS Developer

.nch (namechange) file and version control

Hi there! My question is fairly simple: how should we handle conflicts in the .nch file when merging different branches in a version control system? When two branches originate from the same commit, and namechanges are made, the .nch file contains new lines at exaclty the same line numbers, often (always) resulting in conflicts. Currenlty I resolve these by resolving the conflicts with "mine before theirs” as I tend to want to keep both. The need for this (simple) manual intervention is a bit annoying. What are the alternatives? Could we even simply ignore the .nch file in our git repository? Is there a way to track the file but prevent conflicts? I would like to hear your thoughts!

2 years ago

graleoNewcomer

posted in AIMMS Developer

write a code

Dear all, I want to write a code in the MainExecution section. I want to consider in the first cycle a constraint, but I wan't to consider this constraint in the second cycle. How can I write this? Thanks Best GL

2 years ago

pamjsnnNewcomer

asked in AIMMS Developer

MathFourAIMMS Implementation Partner

posted in AIMMS Developer

Not enough memory in awf.data.aimms.session - what's that about?

I can't seem to find any documentation on the error [code]awf.data.aimms.session: Not enough memory. [/code] It only shows up in WebUI, and I know (think) AWF is "AIMMS Widget Factory." I don't have any custom widgets in my project, so I'm not sure why I'm getting this error. Can someone point me in the direction of some documentation on this so I can investigate? Thanks! ~Bon

2 years ago

GertjanProduct Owner

posted in AIMMS Developer

Feedback discussion: AIMMS supporting Python 64-bit only?

As some of you are aware (e.g. as discussed in product updates), we are currently developing an integration of Python into AIMMS. For this development, we are discussing whether we still should support Python-32 next to Python-64 (fyi, AIMMS Developer only will be delivered as 64-bit per 1/1/2020; AIMMS PRO has been 64-bit only for several years now). Curious to hear your thoughts! Please elaborate as much as possible when explaining your view.

2 years ago

AkshExplorer

asked in AIMMS Developer

Error with the Production Model Tutorial Provided by AIMMS

hello,I was studying the tutorials provided by AIMMS and I came across a Production Model in the PDF Document for AIMMS for Professionals Tutorial. I’ve tried to open the file to see if it works but I come across the following errors as attached and it will not let me execute the model. The zipped folder with the model has also been attached for your reference. Thank you for all the help!

1 year ago

mennovaneerselNewcomer

asked in AIMMS Developer

Nearest neighbors for TSP

Hi there, I am trying to implement some form of heuristic for the TSP where I'm decreasing the size of the model by restricting the declaration of variables X(i,j) to those combination (i,j) for which j belong to the, say, 10 cities nearest to i. Here X(i,j) is an binary variable indicating whether or not edge (i,j) is in the tour. I created a subset of the cities to find the nearest neighbors of city i, but how can I implement it in the model? Do I need to add an extra constraint or? Added you'll find the code of my AIMMS project. Thanks in advance!

3 years ago

LowBjornAce

asked in AIMMS Developer

Writing data back to MSSQL table containing an identity column

I want to write back changes to a MSSQL database after reading information from a table. The table is designed to provide a minimum working example and has two columns: ID: ID column starting with 1, increments with 1 VALUE: column containing integer values. I have managed to read from this database table, however, I want to be able to change a value in AIMMS and then write back the change using write p_parameter(i_ID) to table db_TableName; However, this gives me an error stating that I'm not allowed to insert manally into an ID column. This makes sense of course, but how do I prevent AIMMS from trying to insert into the ID column and replace old values by new ones instead?

2 years ago

Zahidah Mohd ZaulirExplorer

asked in AIMMS Developer

More about the progress window

Hi, When I run AIMMS, I’ve got this result in the progress window as shown in the picture attached, I wish to know what they are mean and how they work. Can anyone explain it to me? 1. infeasible 2. integer infeasible 3. intermediate infeasible 4. terminated by the solver 5. solution does not exist 6. solver not called 7. left 8. nodes 9. thread 10. nonzeroes 11. variables Thank you in advance.[img]https://uploads-eu-west-1.insided.com/aimms-en/attachment/84219ee6-380c-4d4d-b0df-5d3bf0fc1883.png[/img]

3 years ago

erika.hashigutiAIMMS Implementation Partner

asked in AIMMS Developer

SQL stored procedure

I’m trying something like this, but compound sets does not exists anymore. Someone could please help me?

2 years ago

pai.b.pradeepAIMMS Implementation Partner

posted in AIMMS Developer

Reading a column from .csv file having data with standard JSON quotes

Hi everyone, I was trying to read a column from .csv file which contains data with standard JSON quotes ("). The CSV reader in AIMMS ignores all the characters after the quotes. Anyone knows a fix?

2 years ago

rezakhaliliExplorer

posted in AIMMS Developer

Binary variable have fractional value

Hi I am using AIMMS for solving a planning problem in electrical engineering field. The optimization problem is a MILP. I have some variables that are defined to be binary but when the AIMMS solve the problem some of the binary variables have fractional values, which is weird. I should mention that the relax status is used for solving linear version of MIP, but in the case that I am talking about the relax status variable is set to zero to have binary answers. Most of the answers are binary except for some of them that have fractional values. I would be grateful if someone could help me to solve this issue.

2 years ago

OlafAIMMS Implementation Partner

asked in AIMMS Developer

How to raise warning before closing WebUI tab?

Hi All,For a project we are implementing a user is making changes to a relatively large table. The user has the possibility to store these changes in a database.However, when a user closes his/her browser after having made these changes and forgets to store the changes in the database the changes have to be made all over again. Is there a way to raise a warning when closing the browser? In this case that would refer to a user that has made changes, but has not stored them in the database.I know using a uponleave procedure works when navigating to a different page, however when closing a tab no warning is raised using such a uponleave procedure. Furthermore, I have seen multiple sites raising a warning when closing the tab, so curious to see if this is possible to do in the AIMMS WebUI as well!

1 year ago

User SupportAIMMSian

posted in AIMMS Developer

Overview: Deprecation of Compound Sets

In May 2018 AIMMS announced a plan to deprecate compound sets in stages. Support for compound sets will be fully deprecated [b]after January 1, 2020[/b]. To find out how to identify and remove compound sets from your model without losing functionality, read [b]AIMMS Knowledge:[/b] [url=https://how-to.aimms.com/Articles/109/109-convert-compound-sets.html]Prepare for the Deprecation of Compound Sets[/url]. This article provides the following background information: [list] [*][url=https://how-to.aimms.com/Articles/109/109-deprecate-compound-sets-overview.html#section-what]Definition of compound sets in AIMMS[/url] [*][url=https://how-to.aimms.com/Articles/109/109-deprecate-compound-sets-overview.html#section-why]Reason to deprecate compound sets[/url] [*][url=https://how-to.aimms.com/Articles/109/109-deprecate-compound-sets-overview.html#section-when]Timeline to adapt your model[/url] [/list] Here is the [url=https://how-to.aimms.com/Articles/109/109-deprecate-compound-sets-ov

2 years ago

inkognitroExplorer

asked in AIMMS Developer

Export to Excel: Spreadsheet vs axll

I want to write data in Excel. Generally “Spreadsheet::Assign...” commands work fine. However, I fail to include zeros in the output in Excel. I want this:i/t 1 2 1 0 0 2 5 7 I get this:i/t 1 2 2 5 7 Now I found the “axll::” library and the axll::WriteTable command, which seemed promising. Unfortunately this seems to work differently, since commands need an open workbook, which the “spreadsheet::” commands don´t. Combining both worlds doens´t work either. Can someone help? I am very confused. Thanks

1 year ago

stefan1991Newcomer

posted in AIMMS Developer

Minimizing Changeover Time in Scheduling Problem - Computation time

Hello, At the moment I am performing a scheduling problem with time windows. The model is very similar to the second model which can be downloaded from the AIMMS website (see link) execpt from a number of elements: [list] [*]I try to minimize the sum of all the changeovers that are used. [*]Base unit is in minutes. [/list] In total I have 3 datasets (one for each machine) that AIMMS can read in from an Excelfile, one at a time. Initially, my model is able to solve using CPOptimizer 12.8 for all machines, where each job has to be scheduled after the "StartTime" and finish before an "Endtime". After this solution I would like to decrease the StartTime by one week when a job meets a certain criteria and then solve it again. When I run the procedure that decreases the Startime by one week and try to solve it again it finds a solution for only one of the machines and for the other two AIMMS hasnt been able to find a solution yet after more than 9 hours. For the machine that

3 years ago

sunxinyueNewcomer

asked in AIMMS Developer

How to solve Warning_duplicate_row?

During my usage of AIMMS, I came up with some problems about 'duplicate_column_row_warnings'. I want to know how to solve the following questions:(1)Warning: The rows "MaxPump(PSHU-2Pump,01,Unit-1)" and "MinPump(PSHU-2Pump,01,Unit-1)" are equal in the generated mathematical program "LeastTotalcost". For information regarding potential causes and consequences, see the help associated with the option "Warning_duplicate_row".I wonder what does this mean?(2)where can I find the help associated with the option "Warning_duplicate_row"?

2 years ago

pamjsnnNewcomer

asked in AIMMS Developer

Dimension of Parameter in procedure

Hi! I would like to ask what this error means and how I can solve this: ExcelRetrieveParameter(FINAL DATA.xlsx, nC(v,T,w), C3:ALN22, , 0) failed: The dimension of parameter "nC(v,T,w)" is 3. It must be equal to or smaller than 2. I hope anyone can help me with this. Thank you!

3 years ago

graleoNewcomer

asked in AIMMS Developer

How to do Equality Calculation

Dear all, I have a matrix T(i,j,k,s).I want that for each s, i and j are equal.How can I do this?Best

2 years ago

ChiboEnthusiast

asked in AIMMS Developer

Writing a constraint

Dear staff,I would like to receive some help writing the following constraint for a mathematical model.Within a graph, I define arcs (i-j) where “i” and “j” are nodes. For each arc and node, I also have the following variables and parameters:p(i) binary variablep(j) binary variablea(i,j) continuous variableC(i,j) parameterH(i) parameterH(j) parameterI would like to write a constraint expressing the following conditions:if p(i) = 1 and p(j) = 0, then a(i,j) <= C(i,j)*H(j)if p(i) = 0 and p(j) = 1, then a(i,j) <= C(i,j)*H(i)if p(i) = 0 and p(j) = 0, then a(i,j) <= C(i,j) * (H(i) + H(j))/2if p(i) = 1 and p(j) = 1, then a(i,j) <= C(i,j)If you have any suggestions on how to write the above conditions within a constraint, I will be glad.Thank you,

1 year ago

wietAce

asked in AIMMS Developer

put in loop for writing to text file

Hi, The CSV Export DLL does seem to export 0-dim identifiers. Therefore I would like to use put. However I can't figure out how to obtain the value of that 0-dim variable. I have the next snippet of code, which works fine, but the value of the variable is still missing. [code]for (IndexVariables) do if (IdentifierDimension(IndexVariables)) then !do something else else csv_alt_name := FolderName + IndexVariables + ".csv"; put csv_alt; put IndexVariables + "\n"; put name_of_some_variable; putclose; endif; endfor; [/code] The line "put name_of_some_variable;" prints the value of a variable. But it should of course print the value referred to by IndexVariables. How to do that?

3 years ago

Chris KuipAIMMSian

published in AIMMS Developer

Identifier Naming Convention for How ToHow-to

At AIMMS User Content we made a choice regarding the naming convention to be used and would like to share the considerations we had to derive at our choice. What do you think? What are the considerations you used for the naming convention you use?see Identifier naming convention

1553

1 year ago

liliNewcomer

posted in AIMMS Developer

Errors with constraint programming

Hello,I am a beginner with aimms programmation. I added a constraint which is :sum[t,BackLog(i,t)|t>14]=0But when i compile my model, it gives me this message error: Constraint programming constraints cannot be used in combination with real valued variables, only with integer valued variables, element valued variables, and activities. The real valued objective variable is an exception. The mathematical program "MinCost" has both constraint programming constraints and real valued variables, for instance constraint "BackLogC" and variable "Quantities".Do you know wha should I do ?Thank you !!

1 year ago

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