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XML vs JSON : When discussing both XML and JSON APIs, we must emphasize that both have the same objective, in specific terms it can be said that both are accomplish the same goal. The motive of their uses clarifies the best method for them. Extensible Markup Language or XML is founded hard to learn while JSON or JavaScript Object Notation is very easy to learn. XML is not that much convenient with API or Application Programming Interface in comparison with JSON .  

Dear Users, I have designed a MINLP problem and using AOA as solver. The reason I have to use AOA is my problem has goniometric functions and therefore BARON cannot be used. Also, I am using educational license which restrict KNITRO to solve problem over a specific size. When I solve problem using AOA such that it has initial solution (from a small solved network by knitro or AOA), I get final optimal solution in few seconds by AOA. For example, I solve a 4 node network using KNITRO and use this solution to solve 5 node network by AOA and in this way I gradually increase network size and keep getting result by AOA using solution from previous smaller network. This works fine. But, if I want to solve a network with no initial solution, either I get “infeasible solution” (although it has feasible solution in real) or solution time becomes so high and non-stopping (in hours). I have tried setting a bigger value of relative MIP optimality tolerance and MultiStart and increasing the Maximum

Dear All, I have been trying to use ellipsoid uncertainty in a simple problem that I have.The problem is an assortment optimization. Then, I have the Demand Mean for each products Dem(p) and the Covariance matrix or the variance Var(p,p1) for each par of products. The objective is to select the products what will maximize the expected demand Dem(p) at the same time, penalizes products with high variance. The uncertainty set will be a ellipsoid uncertainty. I would like to create the eelipsoid uncertainty using the uncertainty region like:Demand(p).level - sum[p1 , Var(p,p1) * …………There is a example in the book on page 341. but it’s not clear for me.  Could you help me to model the ellipsoid uncertainty using the uncertainty property? Thank you 

Hi fellow AIMMS users.I need help on formulation of piecewise linear functions. I have read section 7.6 of the AIMMS modeling and applied the concept to the Piecewise Linear transportation example. However, I find it difficult to apply it to my case.This is my case: I have also attached the developed model. When I ran the model, error that popped up is“Outer Approximation cannot handle columns like 'Lambda(Gen1,1)' that are continuous and member of a SOS set” Please, I need assistance on how to go about this. Thanks

Hello everyone,I am trying to implement a supply and demand model in AIMMS. This is the first time using it for me and I'm having some issues. The case is as follows: There are Printer companies that supply books to Retailers. These Printers can send the books directly to retailers, or through crossdocks to be consolidated. I have modelled the set of Printers with index P, the set of Crossdocks with index C and the set of retailers with index R. The case asks for a set of locations as the union of these three sets L = P ∪  C ∪ R. I am not sure how to model this union of sets and can't seem to find any info on this. Does anyone know how to do this?Not sure if it matters, but the amount of Printers, Crossdocks and Retailers should be variable and dependent on an Excel input file. Thanks!

 I want to express “State_CHP=0 when Input_energy(t,conv)=0” and “State_CHP=1 when Input_energy(t,conv)>0”, but there always some errors. I have checked the help manual, but there is no specific example of how to explain it.Thank you very much. You will be of great help to me. Thanks.

We have a winui based Pro app hosted on a server with updated licenses and adequate maximum number of users.                                                                                                                                      However, some of the users seem to have received the following error when they open the aimms pro app. I have noticed this error only with developer licenses in general. Could you advice on a possible cause so we could investigate further? 

I am a new student. After clicking ‘’main execution‘’ button, the progress window is as the first picture, which don’t enough information, such as  the second picture. At the same time, the messages window is like the third picture, having ‘.’ in the window. My code is given from my senior, she can get the right answer in her aimms that is a elder version. However ,in my aimms4.76 I can’t get the answer.

spreadsheet::CreateWorkbook(results/Exercise_7/results_demands.xlsx,Energy_demands) failed: Could not open Excel.  why 

As the title of this question indicates, I am looking to work in developer, but send the solve statement to a pro solver session. (And retrieve the results of course)Two main reasons for this are:In that way my laptop will not be taxed (and overwhelmed) by the models that I am developing In this developing stage I gather date from a database that is not connected to our PRO environmentA workaround that does work is to publish the app including relevant data (as a case to the app). However this is a rather inflexible way of developing. As an extra detail, at this point in time my machine cannot generate and solve the instance in reasonable time, while my described workaround takes a little under 2 minutes.

Dear Community, I hope everyone is well.I'm studying some forecast functions inside AIMMS and would like to know if there is a function to create the forecast using ARIMA, SARIMA or similar method, Thank you

In my model, I am tracking the production date of certain products. It is possible to produce a product at time t, while allocating it to demand on time t+3. However, there is a maximum ‘age’ of a product. For example ‘If a product is older that three days, it cannot be allocated’. Now, given an allocation variable v_Allocate(i_Order, i_AllocationDay, i_Product, i_ProductionDay), indicating the allocation on day i_AllocationDay to order i_Order of i_Product which has production day i_Production day, I would like to restrict the index range to ‘valid’ combinations e.g. production day >= t-3.  If I would restrict the index domain on the variable like so:index domain: (i_Order, i_AllocationDay, i_Product, i_ProductionDay) | i_ProductionDay >= i_AllocationDay - 3 Do I still need to add a separate constraint to ensure this production day restriction? In addition: does it make sense to do this in the index domain? 

Given a set of nodes and directed edges (from parent to child node), is it possible to construct an indexed set S_Children(i_node) that contains all children of the specified node? With all children I mean the set of all reachable nodes, starting from i_node.For example:s_Nodes := {A, B, C}s_Edges := {(A, B), (B, C)}Then I would want:s_Children(A) := {B, C} Edit: The edges are actually defined through a binary parameter. i.e. p01_edge(A, := 1;p01_edge(B, C) := 1;

Hi I am trying to find the Cplex log. It was in the AIMMS program folder but now the AIMMS launcher replaces it and I could not locate the Cplex log. Thanks.

Hello,I am trying to print a custom message at the command-line, while running aimms via a batch-file. The goal is to get an information about the status and the progress of the optimization. I have tried the DialogMessage, DialogProgress and the Display function with no success. Can anyone help me with that?Best regardsJonathan 

In my projects I like to use prefixes such as ‘s_’ for sets and 'p_’ for parameters.However, when designing a webUI page, I would like to mask these names with something more human-friendly. How do I do this?My minimal working example project contains two items:Set s_DummyData { Text: "SetDescription"; Index: i_dummy; Definition: { DATA {1 .. 100}; }}Parameter p_SampleParam { IndexDomain: i_dummy; Text: "ParamDescription"; Definition: { val(i_dummy) * 100; }}What I hoped the Text attribute would do, is replace ‘s_DummyData’ with ‘SetDescription’. Instead I see this when I enter a table in the WebUI: 

Hi,Does anyone know if I can format excel cells from AIMMS? The data that I export contains date and excel automatically converts it to its own date format and changes the defaults AIMMS format. Is it possible to set it as string when writing? Thanks,

In AIMMS it is possible to read data from both a query, or a selected object (e.g. a view). I was wondering if there is a difference in performance between the two methods if the only goal is to read data.In my case, I am considering reading data from a table valued function because that allows me to filter the data according to several parameters. An alternative is reading from a view, where the parameters would appear in the columns and then used as an ‘Index domain’ when reading the database table in AIMMS.I’m generally interested in performance impact, best practices, and overall trade-offs between alternative data retrieval methods (given a database).

Hi Aimms Community,  I’m having trouble using the Sort function in order to obtain the values of a mulit-dimensional array: For example:multi-dimensional array = foo(size,car,color,location)             size, car, color, location = some float value [ ‘small’, ‘toyota’, ‘white’, ‘usa’] = 1.25 [ ‘small’, ‘toyota’, ‘green’, ‘greenland’] = .5 [ ‘small’, ‘nissan’, ‘blue’, ‘france’’] = 1.0[ ‘small’, ‘nissan’, ‘green’, ‘france’’] = .3 In this case we are looking to sort foo by the values for all colors and locations where the size and car are the same, meaning that the result would be put into another variable  bar(size,car,row)[ ‘small’, ‘toyota’, 1] = .5[ ‘small’, ‘toyota’, 2] = 1.25[ ‘small’, ‘nissan’, 1] = .3[ ‘small’, ‘nissan’, 2] = 1.0 How do I approach this problem? I looked through the documentation but I see that the Sort operator is really trying to sort by an index of an array and not the values for given indexes.  Thanks for any help

I have an old optimization from 2 years ago that uses CPLEX 12.9 and ODH_CPLEX 4.0. I want to change the solver to CPLEX 20.1 (which is available in AIMMS 4.81). However, the list of AllSolvers does not include the new CPLEX. (nor ODH-CPLEX), so I cannot change the default to the new version. Is there somewhere else in the model that need to be updated for the list of solvers to update?

Hello, I am trying to read a db file on Cloud but it is showing the error attached herewith.Description:I have created a parameter that reads value from the database Output.db with procedure ReadTable. Also, I have created a procedure AddRecord to add record to the database. I exported the aimms file to aimmspack file and uploaded it on Cloud. But it is not performing the as expected.Could you please help me with this problem? I have attached the model as well. Thank You,Vishwesh Patil

Hi. I am trying a generate a plot of optimality gap vs solution time. For that, I am trying to retrieve incumbent solution, best bound and solution time after every 5 iterations. But, for some reason, I am having issues with callback and I don’t get anything retrieved. Attached herewith are the images giving implementation of callback operation. Could anyone please tell where I am going wrong? Thanks,  Sujit

Dear all, I want to find the point on the pareto front (obtained with the epsilon constraint method) that has the minimum distance from the utopia point. How can I do this in aimms? Thanks Best Grazia

Dear All,Is there a way within AIMMS to implement Bilevel Programming as shown in the image?Thank you for the advice given. 

Hi,I was wondering if there was a way to automatically publish an application or upload a .aimmspack file to AIMMS PRO, more specifically on the AIMMS Cloud Platform.Thanks, Rodrigo.