AIMMS Language

Is there a parameter that shows if the solution is unique when using CPLEX? 

I am trying to open a project that was written in AIMMS 4.37 with AIMMS 4.88. Upon opening it, the window shows ‘compiling’ at the bottom for a few seconds before crashing and closing down. Is this to be expected?Is AIMMS 4.88 compatible with projects written in older versions?Should I expect to see an error message instead of the whole program crashing? Any help would be much appreciated! Thanks,, Sandip

Hello AIMMS community, I am trying to create a mapping file to read a JSON file using Data Exchange Library. The JSON file is structured as follows:Data: {"CaseTable": [        {            "Case": 1,            "Specification": "Specification 1"  },        {            "Case": 2,            "Specification": "Specification 2"  }]’ "PriceTable": [        {            "Contract": "X",            "Specification": "Specification 1",            "Price": 100  },        {            "Contract": "X",            "Specification": "Specification 2",            "Price": 200  }]}As can be seen, the JSON file includes two tables: "CaseTable" and "PriceTable". I want to read price from PriceTable and assign it to the Price_Parameter(i_case, i_contract) which is indexed over “Case” and “Contract”. For example the value of this parameter should be 200 if the Case 2 and Contract “X” is selected:Price_Parameter(2, X)=200. Case 2 is related to the Specification 2 (according to the CaseTable) and the price

I have a multi-indexed parameter, say pMatrix(i,j). I want to efficiently get the first element of the matrix.Applying the First-operator (i.e. First((i,j) | pMatrix(i,j))) did not work; it results in the following error: “The iterative operator first can have only one iterative index.”I can think of some workarounds (such as to start by finding the first i, and given this i finding the first j), but this is quite cumbersome, especially when there are more than two indices (in our project we sometimes have up to 7 indices).How should this be elegantly addressed?

This article discusses some elements from the popular software methodology Test Driven Development in relation to the AIMMS Library AIMMSUnitTest. Gather requirements from stakeholders What are small examples? What are the edge cases, including error cases, performance? Implement requirements as unit tests and see them fail! Development Write the code for the functions Execute tests and see them pass! Refactor until performance is acceptable. Repeat Read more...

In the new version of  aimms, the “data manager button” does not exist. I used to run multiple instances as a batch file using the data manager. I saw the “select multiple case files option” but I could not figure out how to use itto run a set of instances automatically. I appreciate any help in advance.

Existing successful applications often have several features. To realize all these features there is a significant body of code.An application developer may be faced by a small change that causes significant differences in runtimes.Examples of such small changes are:a change in data,  a code hotfix,  a switch of computing environment, or two different persons operating the application.The location of the code where these performance differences manifest themselves may not be obvious. Facilitating the adage: measuring is knowing: the AIMMS engine provides the diagnostic tool: AIMMS Profiler.The AIMMS application ProfilerRunCompare is a small tool to compare two profiler runs. Come and check it out here.

Hey! I'm trying to export using AXLL and have been able to write single variables and simple composite tables, but can't figure out how to slice a variable. I'm not sure if this is something I haven't learned about Sets or something with WriteCompositeTable.I want to do this:my_set := {A(x, ‘Blue’), B(x)}axll::WriteCompositeTable(              IdentifierReference : my_set,             TopLeftCell : "A1");It's the ‘Blue’ part that I can't figure out.Thanks in advance!

Hello,I have a question related to writing a result to excel. I know how to write a matrix from a single parameter to excel, however I have trouble constructing a single table where all values match. If I have a parameter location(city, xy), where city is a set’s list, while xy has two columns (latitude, longitude), and I would like to combine with parameter Client(city,client), and parameter DistanceClient(city, distance), and parameter ClientDemand(client, poroductdemand), how do I save this data into one table where the rows and columns match?NOTE: each city has different number of clients: city1 has 4 clients, while, city2 has 8 clients, etc.How to obtained the following matrix in excel that looks like this:               latitude     longitude    client     distance   productdemand  city1city2city3….cityn  I’m really appreciate your help :)Kind regards

Hello AIMMS Community!I’m looking to understand if it’s possible for AIMMS Data Exchange Library to read an excel file that is structured something like this (modified from the sample on the DEL documentation for EXCEL):In this structure, we have an excel sheet called “Table1”. The table on this sheet has two columns that map to an index (set1 [i], set2 [j]), two parameters that are defined over these indices (d1, d2, d3) and a child table that uses the two defined indices and a third index for time that maps to a parameter p_test(i,j,k) . Where k is defined by set in columns (Time-1, time-2, time-3). I’ve been able to successfully read d1 and d2, but I’m having trouble understanding if it’s possible to read a third index in the column.  The current documentation does not describe thisThe motivation for using DEX in this case is that we have have existing XML files that read the same data from JSON (output from database calls). We’d like to leverage these XML files to create excel mapp

Dear AIMMS community group,I’m currently working on modelling an Inventory Routing Problem in AIMMS based on below model formulation to minimize the total transportation and inventory cost.I have created a project in AIMMS as enclosed, however despite no errors I don’t receive a solution (solution is total cost of 0).Therefore, hoping someone can support to have a look at my model and advise on what might be wrong and how to solve to generate the solution.I’m attaching you my AIMMS project as well as the model formulation that I’m using.Thanks a lot in advance!

Hi everbody,I want to generate an integer parameter that contain whole data from the table in one line, where the values for the same row are sparated by “,” and values of each rows are separated by “|”.Wish the final result looks like that:“1, 2 | 3, 4 | 5, 5 | 6, 7 | 8, 9 | 12, 0”Table:Location\XY Lan Long Place1 1 2 Place 2 3 4 Place 3 5 5 Place 4 6 7 Place 5 8 9 Place 6 12 0  The data is located in the parameter(cityID, XY). Where CityID corresponds to list of cities, and XY has two possible values “Lan” and “Long”.Thank you for your help :)Cheers,

Hello,I have a problem with Aimms, I tried to program a Gantt Chart and a Calendar. For excercise I followed the Demos. So my question is after I wrote the program where can I see the Calendar or the Gantt Chart ?Do I have to use the widget or install some other extension ? Thx for your help

Hi, Is there any attribute which can ensure that only nondefault values are written to Excel?Like axll:WriteTable function has writeZeros argument and if it is set to 1 then zero cells will remain empty. Thanks,Lilla

Hello everyone,  Is there a way to use a discrete uniform distribution inside of Aimms? I know there is a uniform distribution but it gives me real number values for my parameter. Instead i just want integer values to be drawn from the uniform distribution. Is this possible?  Thank you for an answer. Kind regardsAlex

Hello everyone,  I have an Element Parameter PredecessorOperations(i_operation) that holds the value of the operation that has to be executed before i_operation. With the following statement i want to check if the EP has a value or not:  if (val(PredeccesorOperation(i_operation)) = 0) then….endif; However this only works if all values of the Ep are empty. If any operation gets assigned a predeccesor (e.g. Operation1) then i get the error: Cannot compute the value of string “Operation1”. If I would casually formulate the code it would look like this: if( PredeccesorOperation(i_operation) is empty ) then ….endif;So my question is: What operator do I need to use in order to check if the parameter has any value or no value assigned? I am thankful for any advice you might have. With kind regardsAndrew 

Hi folks,I’m doing some tutorials in AIMMS and I find that the data exchange library is missing from my AIMMS version. Can anyone point me how to install it? This is what I currently see: ThanksLS

Hi everybod,I have a quick question and hope you can help me.I calculate in my model the optimal stock level depending on the period and szenario specific demand.The inventory level is defined as follows: Inventory_PreviousPeriod + ProductionQuantity_CurrentPeriod (also a variable) - DeliveryQuantity_CurrentPeriod.How is it possible to preset the variable stock for the first period to a fixed inital value (in this case the opening inventory)?I would be very grateful for your answer!Best ragards, Hans

Hi everyone, I need to make a simulation in Aimms to simulate the mechanism on the following picture:   Order Release Mechanism I have no problem in declaring all the sets and parameters, but my main 2 problems are too make the periods pass correctly and repeat all processes in the periods and too update the loads and sets at the right points in time.  I have too do this via simulation so without an objective function thats also something that throws me off cause i cant use a Mathematical Programm so solve this.  Maybe the solution is simple but i havent ever worked with Aimms and that is a very big project for me, which is also very urgent so i really appreciate any help i can get.  With kind regards AlexPS.: The programm i made so far is attached as a zip-file. Maybe u can tell me how i need to adapt it to make it work. 

Dear all,  I am fairly new to Aimms, but for my thesis i need to solve a model in Aimms that has no objective function. Its like a scheduling problem, but it must not be optimization based.  So i have most parts of my Model but i dont no how to implement it since i cant use constraints and the solver. One Idea i had was to just make an irrelevant Objective function, let the Solver solve it and have my other parameters (Which Order goes to what station at what time and what is the capacity at each station) as results of the simulation. Would this work or is there any other way i can set this up properly? Thank you in advance. With kind regards, Andrew

Hi AIMMSians,I have formulated an NLP model with around 2500 variables and it is non-convex. When I solve it using IPOPT, I get the error “Intermediate Infeasible, terminated by solver”. When I use CONOPT as solver, I get same error. Analyzing the listing iteration log files, it reveals that solver labelled the solution as infeasible because the convergence is too slow as demonstrated by message in the end of listing iteration log “Convergence is slow and a derivative is discontinuous”. Please note that sometimes, the same model reached a “local optimal” with sensible values for the variables. With some nice information in AIMMS documentation, forum and webinar, I have tried scaling option, good initial points (which are not possible in every case) and a bit of reformulation by removing some variables acting as intermediate variables between two variables to calculate some values. None of these options have proved any change in the results. Any idea or word is highly appreciated. Thank

Hi everyone,I have been trying to call an AIMMS (academic license) procedure from python although this doesn't seem to work. I got the following code from another thread, which seems to work with a paid license. I also saw on another post that the academic licence might have some limitations in this regard. Is there an API in another language, were I can make Python wrapper around this other language?orIs it possible that AIMMS internally allows to run scripts in some language, in which case a script can be built  in such a way that they exchange model parameters/inputs/results with the outside world? Best regards,

Good day people….i am new to AIMMS. I want AIMMS to read from a dat file but it keeps giving me the  statement “The symbol ";" is not expected.” The content of the dat file is  COMPOSITE TABLE:G  M P R_M R_P!-------------10 8 4 10  15 ; after removing the symbol ; it pops up another error which is ‘The symbol "15    " is not expected.’after removing 15, it pops up another error which is ‘The symbol "10     " is not expected.” Is there something i am not getting right on how to structure the contents in dat file. Kindly help please.  

Hi All,I want to compare two scenario for better understanding of output data. And i want to do it from WebUI.Help me to built my Model with such capability. Thanks