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Hello, I have a problem.I created two sets i and j for the variable X_i,j.Now I want to add a constraint to see if the sum of all X_i,j with i="specific value” is equal to 10.My guess would be something like:sum[ ("Specific value”,j), variable(i,j) ] = 10;But this obviously doesn't work, otherwise I wouldn't be asking.

The variable X is with the index domain i, while the variable Y is with the index domain j. The number of element in j is twice that of i, which means J = 2*I when seeing these two index as number.Now I want to write a constraint:X(i) <= Y(2*i)How can I do this in AIMMS? 

Hi, I am trying to model the following constraint:with x as a nonnegative value indication the hours processed of job j-1 in time bucket t and Y as binary variable indicating that job j in time bucket t may start or not. The problem is that t is in the index domain and I need a summation over t’ based on t. How can I properly model this? I already have two indices for the set time buckets: t and h. But how do I model that x(i,j,t) is the same as x(i,j,h)? Preferably in one variable if that is possible? If I just simply say x(i,j,h) in the constraint I get the error: The parentheses in variable "x" do not match. Which is true since I modelled the variable as x(i,j,t).  

Hi! I’m working on my small project and I’m a beginner in programming and AIMMS. I tried to run the model that I have developed but it resulted into “Warning: After zero iterations CPLEX 22.1 concluded that an integer solution to MinimizeDailyCost does not exist.” I attach my model and data.I’m not sure where to start rectify this problem. Appreciate if anyone can help.

Hi,I am solving a huge MIP (481707 integer variables). I set the relative gap to 0% from CPLEX MIP settings. With such a huge model, the solver should take quite some time to solve. Just after 287466.11 sec (3.3 days), the model stop running and the solver status says 'Terminated by solver' why the gap is 1.27%. Why does this happen? I am attaching a screenshot. I'll appreciate any ideas on this. Thanks ! 

There is a time series variable A={a1,a2,a3...at}, and I want to constraint the fluctuation of the variable. I did this in AIMMS with the following way:1) I define a variable series_mean to calculate the mean of the series, 2) I define a constraint to make the variance of the series be no larger than 10000.   series_mean = sum(t,A(t))/T;sum(t,(A(t)-series_mean)^2)/T<=10000; However, this seems burden the computation and the solving time soars even though the constraint didn’t work in optimization. Like in one scenario, with or without the constraint I get the same result, however the solving time with the constraint is 10 times that in the case without this constraint. (The constraint is a must though) .So I hope to know is there a better way to do the same things in AIMMS?Thanks.

Dear AIMMS team, Trust you are doing well. I recently installed AIMMS version 4.94.3.3 and I only found two solvers namely: CBC 2.9 and IPOPT 3.11. I tried adding more solvers to it through the solver configuration but proved abortive. How can I add the following solvers to the version.Conopt, CPLEX, Baron, CP Optimizer, Gurobi, COPT, MINOS, ODH-CPLEX, OCTERATH, PATH, KNITRO, NETSOL. I have also attached the messages I am receiving. Thank you. 

Hi, Is there any way of looping through a for-loop backwards? The subset is ordered by user, for example {1,4,3,5}. I want to loop backwards so from 5 to 3 to 4 to 1.   

I defined a set with the element {1..25}, in the data it shows like the figure. What’s the matter? 

Is there anyway to export the convergence process in one solve?

Hi everyone, is there a predefined function to get the absolute value of variables? 

Hi, I am modeling a multi-commodity network flow. Bing chat suggested the page https://documentation.aimms.com/aimms3/application-development/modeling/network-flows/multi-commodity-flows.html, but it is a deprecated link. Can you provide any such example?

Hello! We are working on a project where data files are stored in central storage following an optimization. We would like users to be able to view and load those case files into a session at a later point in time. We store these data files in a PublicData folder for all users to use. However, regular users are not able to see any of the folders/items, no matter what the permissions of a file/folder are. Am I missing something regarding how central storage viewing works?  Looking forward to your answer!

Hi all, I want to read data from Excel but it should be sorted customly. In Excel the data is like this:  The result in AIMMS should be this:  I can create this with a text join in Excel and paste the value in the data field in AIMMS but the data changes frequently so I want to automate this with AXLL functions. It is important that the order of a, b and c holds.  Does anyone have an idea to do this? 

Hi community!I have a problem about a formulation and I am looking for help!I have defined a set “Input” index i, and two subsets “input1d” index id and “input1s” index is. Here is my formulation of a constraint:Identifier : MassConservation12Index domain : (i,id,is,r)Definition : sum(t, S1(i,t,r))+Stock1(i,r-1)=sum(d, Y1(id,d,r))+sum(s, uu1(is,s,r))+Stock1(i,r)+ZZ1(id,r) Should I modify the index domain in order to make clear that id and is are subsets of i? Thank you!

Dear AIMMS Team,Trust this meets you well? Kindly assist on the problem explained below and find attached the AIMMS file I am working with.   I have a variable StateofCharge(t) in which t is 1 to 24.  I want to place StateofCharge(t) at t = 1 or StateofCharge(01) on the conditional statement below. if ( (Charging_Power_kW(01) + SoCMin) > SoCMax) then     SocMax      elseCharging_Power_kW(01) + SoCMinendif;Note: Charging_Power_kW(01) is put as the value of variable Charging_Power_kW(t) at t=1 While StateofCharge(t) at t = 2,….24 should have the conditional statement below. The index t in the statement applies only from t = 2,….24. If Energy_Difference_kW(t) > 0 then      if (StateofCharge(t-1) + Charging_Power_kW(t)) > SoCMax       SoCMax       else       StateofCharge(t-1) + Charging_Power_kW(t)     elseif (Energy_Difference_kW(t)) < 0 then       if (StateofCharge(t-1) - SoCMin) > Discharging_Power_kW(t)       else        SoCMinendif; Also, if I have a parameter/variable

The objective variable is A(t) contains t = 1 to 24. The mathematical program is to maximize the sum of all the elements in A, i. e. Max sum(A(t)), t = 1 to 24. At the same time I hope to constrain the property of the objective variable that the standard deviation SD(A) is no larger than a constant “a”. So I defined a variable “SD(A) = standard deviation of A”. Then a constraint “SD(A) <= a”. When I run the program, it reminds me of “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 has both constraint programming constraints and real valued variables.” However, when I revise the constraint from inequality to equality, i.e. SD(A) = a. Then no error arises and I get the answer. Why dose this happen? And How can I deal with it if I want the inequality constraint?

Hello all!  Is there a way to hide thousands separators in WebUI? We want to have years displayed in a scalar widget (e.g. 2023), but currently, WebUI automatically adjusts this data (e.g. to 2,023).  Thank you in advance for your help!

I want to run the model with different scenarios (data), can I import all the scenarios once and get the result for each scenario in one run?

 Like one day have 24 hours, I need to calculate the variables for 24 periods, but these variables are defined by 25 points, so I define the index t as “25”. For example variable A contains 24 elements, A(1) = B(2)-B(1)…...A(24)=B(25)-B(24).  If I define an index “t” as 25, I can simply define the B as B(t) using t (1 to 25) as the domain. But How can i define A which only contains 24 elements, actually from 1 to 24, can I use part of t domain from 1 to 24? 

I have a string parameter as per the following data```optimalfeasibleinfeasible```I would like to show it in the WebUI in the same way but it is coming as ```optimalfeasibleinfeasible```Kindly help. 

Hello everyone,I’m new in AIMMS and need help for my thesis. I need to implement the following constraints: t is an index for the period, here t = ( 1,2,3,…,T )How can i set the initial value from E(t=1) = Q How can I implement the E(T+1)  Thank you in advance kind regards  

I have a question regarding the calendar. We have an old app implemented based on calendar, in which the hours within a day are expressed as 00 ~ 23. But now we need to change it to 01 ~ 24. Please let us know what the easiest way to do it.

Hi Community, I am trying to use the AIMMS RegexReplace function to trim the folder path and keep the data case name. It’s working fine locally but it’s not working when testing in the server.My code looks like this:        block ! Get the full path for the Active Case File            _sp_ActiveCasePathName := FormatString("%s", CaseFileURL(CurrentCase));            !Check for server vs local. Local path won't likely contain the string 'PRO:/PublicDta'            !example server path: PRO:/PublicData/Cases/spot_fw            _bp_IndicateLocalFileName := not (RegexSearch(_sp_ActiveCasePathName,         "PRO:\\\\PublicData"));            ! Text example _sp_ActiveCaseName := "C:\GitHub\spot-fw\Model Folder\data\DataCase_C5AgeTest_Output.data"            ! This Removes the structure             !local: C:\\Location_of_File\With general\ideas-of-how\afilesnamewouldbe\             !in the server: pro:/PublicData/Cases/FW SPOT Testing/            !before the actual file name            if _bp

Is there any existing library or repository library available to calculate inverse matrix, especially for large scale matrix?