AIMMS Language

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?

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!

Hi,If anyone can clarify the difference/similarity between Current Case and Active Case that would very helpful. Thanks,

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 simply need to make a subset “test” of range from 0 to 10 of set “timehour” which the range is from 0 to 140 But I don’t archieve to do it see picture.When i range “test” from 0 to 100 or more It works but when I’m below 100 it doesn’tHelp me pls   

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.

Hi,  I am wondering if it is  possible to set a specific value for the best LP bound of  a  Mathematical program (before executing the Mathematical programof course)? Thanks

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 

I’m using CSVProvider 1.1.1.2 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 ?

Is there a way to lock a page in Web-UI with a password?

I’m trying to define a limit to RAM memory available to solve a generated mathematical program. Is this function related to this? I tried code below, but it’s stoping my solve before the time_limit defined, before the the GAP defined and also is not using 24 GB available. And before I changed the code to use gmp functions it was taking more than 11 GB.   

Can AIMMS  interface  Python，such as tensorflow？

Hi,I want to build a model that can transport stuff from (i to j) directly or by stopping over at facility r.The transportcost (i to r) and (r to j) are cheaper than the direct transport (i to j). Problems:Open(r ) is either 0 or all possible r are opened and the amount is divided up evenlyEven if transportcosts are way lower for the extrastop r than without, the model does never choose to move all products past extrastop r. (capacities are more than enough)  (goal is to minimize total cost (fixed cost and transport cost included)Related Constraints:Amount(i,r)+Amount(d,r)<=Demand(i)*OpenRecycling( r) // index (i,d,r) sum(i,Amount(i,r))+sum(d,Amount(d,r))<=Capacity(r)* Open( r)   //index (r ) sum(r,Amount(i,r))+sum(r,Amount(d,r))=(Returnrate(i)*(demand(i))) //index (i,r) sum(i,Amount(i,d))<=Capacity(d)*open(d)      //index(d) sum(i,Amount(i,d))=sum(r,Amount(d,r))         //index(d)  Thanks for your help.I´m more than happy to post my model if that helps

Hello, for a submission I just had to download AIMMS. I have applied for the Academic License to use it. After I received the verification mail, I proceeded exactly as described in the mail. However, I still can't really use AIMMS because I always get the following error message when creating a new project. As soon as I want to open another project, I also get an error message. When I want to implement a new model I can't add new sets, parameters etc. either. Any help is highly appreciated! 

I have a Binary Variable X(C,V,T).Suppose for  t  and v  , X(c,v,t) is 1 for a c1  in C.I have another element parameter/variable (Range in C) F(V,T).now using this variable X how can i find F(v,t) = c1    

Hi, I these days, I realized a new limitation with the new academic license delivery. Before, I was able to run two instances of AIMMS at the same time. However, now I can only run one instance at a time. Here are my two main uses for parallel instances of AIMMS:I am dealing with a quite heavy energy system model that runs around 2 to 20 hours (depending on the level of details). Sometimes I need to run several scenarios for a specific sensitivity analysis. It would be very useful for me if I can run the model on several computers at the same time. Sometimes I want to continue coding in AIMMS while it is running a problem.  Would it be possible to run two or more instances of the model at the same time for academia? 

I looked into the example of the dex:: library and I tried the DataExchange example. However I still have trouble to get started in my own program. I want to read a JSON file like given in the attachment and use the data in some variables in my AIMMS program. Could someone help me with a simple example program?

Hi, I used to watch two aimms videos, one of them was about performance tunning of problens and the other was about infeasibility of models, but after the chanegs in the site I cannot find then anywhere. Doesn anyone remember of these videos and where to find them?