Topics about getting started or leveling up as an AIMMS developer. Datalinks, AIMMS language, building apps...
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Hi AIMMSians, I am using the AMD 3995WX processor which has 128 logical processors. I realized that a single instance of AIMMS only uses 64 logical processors as processors are grouped by windows’ limit (64 cores). To use all 128 processors, I can run two instances of AIMMS at the same time. The first instance gets affinity of group0. Then I need to modify the affinity of the second instance to use the second NUMA (group1). Still, I would like one instance of AIMMS employs all logical processors. I assume the same problem exists on servers where the number of logical cores often exceeds 64. Is there any way to bypass windows' processor group policy (i.e. make AIMMS group aware) and distribute the job between all 128 available threads? Note 1: I tried CPLEX and GUROBI solvers. I am not sure if this limitation is related to AIMMS or the solvers.Note 2: I am aware of disabling Hyperthreading/SMT, but that is not desirable.
Hello everyone, I am new to AIMMS and I think I like it because of its graphical user friendliness. I want to use AIMMS to optimize the charging profile of a number of vehicles in a decentralized way such that the original central problem is decomposed to be solved independently as a subproblem by each vehicle. This is to be done for vehicles 1 to N over a number of time steps. I discovered this is difficult for me because the objective function in AIMMS is usually a scalar. Please, how can I do this? thanks
Good morning and a very good day to you!Dear Sir / Madam,Currently, I am running big data using AIMMS for my Final Year Project to produce an optimal exam timetable. My MIP model consists of 1 decision variable, 3 objective functions and 14 constraints.I encountered the same problem for many times when I was running my data. I realized that AIMMS will usually shut down on its own after running for more than 2 hours before even getting the results. I have checked my computer to see if it has any technical problems but I have not found any. Can you please help me with this problem? I am attaching a relevant picture for your further references. I am looking forward to getting a favorable reply from you soon. Thank you for your time and patience.
hello everyone,i have a question about my aimms project:i have two variables: x(t,k) and y(t,k)now i want to determine, thatif x(t,k) < y(t,k) then y(t,k) = x(t,k)i already know that this is not possible with an if-statement.has anybody an idea? Thanks in advance.Seb
Hello everyone,i'm just a beginner and have a few problems with aimms. I am investigating a warehouse in which customer orders are split up into partial orders. Each partial order is assigned to a zone.My problem is that Aimms assigns the partial orders to multiple zones instead of just one. In the attachement you can see that a partial order is assigned to several zones. j are the partial orders; z are the zonesIs there a way to say in a constraint that only one value can be assigned? Thank you!!!
Hi, I was using the GeoFindCoordinates function in AIMMS to map a given city name to a lat/lon combination and received an error message all of the time. Then I remembered I was on VPN and maybe there was an issue with the connectivity, so I disabled my VPN connection and tried again and the GeoFindCoordinates was able to execute without a problem.Whenever I am connected to the VPN connection at work, all my outgoing connections must go via a proxy server. Almost all programs I am working use the standard http_proxy and https_proxy environment varaibles, but it looks like GeoFindCoordinates is not doing this.I know there was a possibility to provide proxy settings for activating a license, but I can’t seem to trigger that option (as this seems to use my IE proxy settings).Is there any other way that I can set the proxy settings for this function? Also, could there be a potential for any other functions (like calling webservices, etc) that make outside HTTP(S) connections that they do n
AIMMS functions and procedures use local identifiers to hold the values of arguments. The model editor functions that form the basis of runtime libraries operate on elements of AllIdentifiersThese functions create, modify, and delete corresponding global identifiers in the model. In other words, they do not operate on local identifiers. This short tutorial by @Chris Kuip teaches you to add local identifiers to AIMMS procedures and functions that are created at runtime.
HI, Having the Math Program Inspector is one of the great add-ins of AIMMS. One of the features that I really like is the matrix summary, where I can see the smallest and largest coefficients. However, I want to identify which variables and constraints are involved in those smallest or largest coefficients. One way is to look at the matrix graphical representation, but my model is big and I couldn't find those small coefficients. Now I have some e-14 coefficients that cause numerical instabilities. I was thinking to scale my model, but I would like to find the variables and constraints related to this e-14 coefficient. Is there any way to find the smallest or largest coefficients location in the matrix, without looking at the matrix graphical representation?
Error message: The constraint "Balanceinv" without a suffix cannot be used inside the definition of a constraint
Hello community!I’m trying to encode my inventory balance constraint on AIMMS but when I click on “Check and close”, I receive this error message: “The constraint "Balanceinv" without a suffix cannot be used inside the definition of a constraint”.Has anyone experienced this problem before and can help me? I would be very grateful!
Hello everyone,I have been using AIMMS for a short time and am still a beginner.When I encode my objective function, the following error message appears : “the scope of index “m” has not been specified”.I have tried several ways to solve this problem but none worked.Has anyone experienced this problem before and can help me? I would be very grateful!
Hello,I am trying to create Tables in a database using DirectSQL() function. There are 3 scenarions: DirectSQL("DRIVER=SQLite3 ODBC Driver; Database=Output.db","CREATE TABLE April2121 (Field1 INTEGER)"); Here the procedure is succesfully executed DirectSQL("DRIVER=SQLite3 ODBC Driver; Database=Output.db","CREATE TABLE 20210421 (Field1 INTEGER)"); Here it generates an error DirectSQL("DRIVER=SQLite3 ODBC Driver; Database=Output.db",FormatString("CREATE TABLE %s (%s INTEGER)",CurrentDate, Field1)); Here it generates an errorI need to create tables with names taken from string parameter “CurrentDate” and Column Name taken from string parameter “Field1” Current Date string parameter is defined as CurrentToString("%c%y-%m-%d").Could you please tell me where I am going wrong with this? I have attached screenshots for your reference.Thanks.
Hi.I am trying to solve a large problem in parallel using asynchronous solver sessions. However, I get this error as soon as I start the simulation ‘The number of simultaneous solves by solver 'CPLEX' exceeds the license limit of 1.' I have CPLEX (Full) solver in AIMMS. Is this because I have a personal node locked AIMMS business license? How do I check the number of solver sessions that I can run simultaneously in AIMMS? Is there a way to activate the Parallel CPLEX option? Thanks.
We try to make AIMMS as easy to use as possible, but there are times when you’ll run into errors with your model. Here are some tips to report and troubleshoot an error. If you post an error in our community, follow these best practices to get help as swiftly as possible:Indicate your AIMMS version and provide as much context as possible. Share your AIMMS project following these steps, so we can reproduce the issue. Include the reproduction steps in your error report. For example: Open the attached model Run procedure Proc_MyProcedure You should see an error The scope of index "i" has not been specified. Include screenshots in your post.Try searching the community to see if someone else has encountered this error as well. You may find the solution you’re looking for. Thank you for your report! It helps us all
HI everyone, so I have to model a problem but when I run the procedure, it tells me: Warning: CPLEX: Q matrix is not positive semi-definite.Warning: Model status 13: Error no solution, Solver status 9: Error: Setup failure (see message window).I have no idea where my mistakes are, that's why I come to ask for your help.so here is my problem :I have 4 variables, X(j,i) and Q(i,l) are non negative and Y(i) and E(i) are binary variablesMy function to minimize is : sum( (j,i), csb(j,i)*X(j,i) ) + sum( (i,l), cbd(i,l)*Q(i,l) ) + sum( i, ce(i)*E(i) ) + sum( i, co(i)*Y(i) )My constraints are: sum(i, X(j,i)*Y(i)) <= capmp(j)sum(l, Q(i,l)) <= capb(i) + 50*E(i)sum(i, Q(i,l)) >= ed(l)8.333*(sum(j, X(j|j="Afyon",i))+sum(j, X(j|j="Konya",i))) + 9.091*sum(j, X(j| j="Import",i)) = sum(l, Q(i,l))sum(i, Y(i|i="Istanbul")) =1sum(i, Y(i|i="Ankara")) =1sum(i, Y(i|i="Izmir")) + sum(i, Y(i|i="Sakarya")) + sum(i, Y(i|i="Adana")) =1sum(i, E(i|i="Izmir")) + sum(i, E(i|i="Sakarya")) + sum(i, E(i|i="Ada
Hi,I want to read data for a parameter P(x,y) from excel file. The parameter is two dimensional.And the data lies in one of the sheet(say Demand) of a excel file(say DataFile). I have tried ReadList but it is not working as the range of x lies in A2:A50 and the range of y lies in E2:E50 and data lies in T2:T50.Help me to read the data with out creating another sheet.
GOOD MORNING, I TRY TO ADAPT THE PROBLEM DIET FOR USE IN F&B BUSINESSES. HOW CAN I DO TO ROBUST OPTIMIZATION? FOR EXAMPLE THE COST PER PERSON REASULTS SHOWS IN ‘PEAK’ AND ‘BASE’. I HAVE SEEN THE TWO EXAMPLES OF AIMMS BUT NOT HELP ME. I MEAN THE 'POWER SYSTEM EXPANSION RO' AND 'PRODUCTIONPLANNINGRO'. THANKS
Hi,how is it possible to obtain a worse outcome on a more powerful PC system? Are there solver options which are benefitial for a faster PC system?In my specific case, I run a Mathematical Program (MIP) minimizing a target function. Since the computation effort is quite high, I introduce an Upper Bound to reduce the solution set. However, if I run the identical probelm instance on two systems, the more powerful one is not able to even calculate a Lower Bound. I use CPLEX 20.1. Any idea why this could be or how to configure solver options? Thanks and best regards
To properly launch and shut down an AIMMS application, it’s important for a model builder to know the initialization and termination sequence order used by AIMMS. Therefore, in this tutorial, we built a small application to illustrate the order of initialization and termination. There are various other questions a modeler may have regarding the initialization and termination of an app, including:When can you rely on a library to be initialized? How to stop a running application?Check out the How-To by @Chris Kuip and download the sample application to walkthrough the process in detail.
Thanks to extensive checking and clear reporting of incidents, end-users can often handle several incidents in AIMMS apps themselves. For other incidents, they may need to turn to the specialists in their team who know more about the data and the model. To help these experts facilitate this support, the GuardServerSession library gathers and shares information about the sessions executed by end-users.An overview of this library can be found in our new How-To on Incident Handling, created by @Chris Kuip For more on error handling, check out Chris’ course on AIMMS Academy.
I’m using CSVProvider 18.104.22.168 for writing outputs to CSV. While writing, certain rows are missing in the csv file where the variable values were 0. When checking in AIMMS (right click variable → Data) I see the domain still has that index but empty value (which means it is 0). However, while writing to CSV the index where variable values were 0 is missing. Is it possible to either include a blank row or with values 0 for the index position where the variables were 0 ?
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