AMPL Modeling Language
https://groups.google.com/d/forum/ampl
A discussion and help group for AMPL, an algebraic modeling language for optimization problems of many kinds. AMPL lets people use common notation and familiar concepts to formulate models and examine solutions, while the computer manages communication with appropriate solvers.enAmple coding problem
https://groups.google.com/d/msg/ampl/wDDGCdG0d6Y/nPodg9gXIvgJ
Greeting , After I am typing my code and try to load the model it take too long and does not give me any error messagehttps://groups.google.com/d/topic/ampl/wDDGCdG0d6Y
Hadeer AboqamerSun, 01 Mar 2015 04:24:44 UTCRegarding SOS1 and SOS2
https://groups.google.com/d/msg/ampl/HGJ1beAxnT8/YMbB-BLLZ1UJ
Hi guys, I can model SOS1 and 2 logic by adding a couple of extra constraints; or I can use AMPL/CPLEX defined SOS constraints. Which one is better in terms of performance? If I throw in my own SOS constraints, will it be recognized by AMPL/CPLEX? Thanks, Fenghttps://groups.google.com/d/topic/ampl/HGJ1beAxnT8
arr...@gmail.comFri, 27 Feb 2015 15:07:08 UTCDisplay IIS (irreducible infeasibility system)
https://groups.google.com/d/msg/ampl/03DjA7jPJwE/SfqC7-L0JZ0J
Hi Bob, You mentioned that CPLEX can run iis detection after find a problem integer infeasible. I tried that. However, since my model is big. I have a lot of rows with status "non", meaning not in the iis system. This is very inconvenient for me to spot the ones that are in the iis.https://groups.google.com/d/topic/ampl/03DjA7jPJwE
arr...@gmail.comFri, 27 Feb 2015 15:07:04 UTCCould someone try running my MTSP problem
https://groups.google.com/d/msg/ampl/2xJwP3c0xBY/g35EyJZMpyUJ
Hi, i am a student at UIUC working on a Multiple traveling salesman problem. The number of constraints in my mod file exceeds the amount allowed on the student version, which i have installed on my pc. My university does have the full version of ampl installed on lab computers however it alwayshttps://groups.google.com/d/topic/ampl/2xJwP3c0xBY
Greg NetolsThu, 26 Feb 2015 17:15:41 UTCAMPL expanding on RAM and writing contents of RAM to a file
https://groups.google.com/d/msg/ampl/aVMBLVYQVBw/mR-g2bvm3hYJ
I have a small question please. I wrote a large AMPL code to be solved using CPLEX. I ran the code and opened the task manager to see when will CPLEX start working and how much will AMPL use of my RAM. Surprisingly, I found out that AMPL took a long time (around 2-3 mins) and was expanding on thhttps://groups.google.com/d/topic/ampl/aVMBLVYQVBw
Mahmoud Al-AshiWed, 25 Feb 2015 12:04:13 UTCRE: [AMPL 10064] indicator function
https://groups.google.com/d/msg/ampl/9TOE5ZGSodM/gQMYmF3xUcQJ
Your param "fact" is being computed correctly. In fact you could define it as param fact {k in 0..nu} = if k = 0 then 1 else k*fact[k-1]; You can't prevent AMPL from computing fact[k] by multiplying it by zero. Probably what you want is to use an "if" expression to avoid computing fact[khttps://groups.google.com/d/topic/ampl/9TOE5ZGSodM
AMPL OptimizationTue, 24 Feb 2015 18:47:04 UTCPiecewise linear function But Decreasing and having negative part
https://groups.google.com/d/msg/ampl/yS4AG67EevU/sFmCkLo9PaUJ
Dear AMPL users I am trying to implement a Piecewise linear function in AMPL but almost all the examples that i read in the book are about implementation of increasing piecewise function where as i have decreasing function, My curve also contain a negative portion . Can someone please help me ihttps://groups.google.com/d/topic/ampl/yS4AG67EevU
Syed Taha MunirTue, 24 Feb 2015 15:57:41 UTCproblem in solving indexed problems
https://groups.google.com/d/msg/ampl/arnn0HwOOhk/6VaelngqymoJ
Dear all, I've encountered problem when I tried to solve a set of indexed problem (the pescore{i in 1..Bells}). I am not sure where I was wrong in defining the problem. Thanks, Hyperplanehttps://groups.google.com/d/topic/ampl/arnn0HwOOhk
HyperplaneTue, 24 Feb 2015 09:39:18 UTCHow to reuse variables in decomposition algorithms
https://groups.google.com/d/msg/ampl/YaRsRIohfyI/60LE1weLMFsJ
Hi folks, I have a coding question. I have a big machine scheduling problem, which includes job allocation and job sequencing. I'm trying to use decomposition to find a feasible solution: generate the job allocation, then use sequencing model to obtain optimal job start times on each machine. Lehttps://groups.google.com/d/topic/ampl/YaRsRIohfyI
arr...@gmail.comMon, 23 Feb 2015 21:17:03 UTCHow to resolve ambiguity in solve_result_num codes when using Gurobi solver?
https://groups.google.com/d/msg/ampl/hSprxUufuRk/-p6-qYSlcRoJ
Hi, When using the Gurobi solver and a user imposed time limit on the solution time is reached solver_result_num returns 403 as expected, but how do I differentiate between the two cases in which a feasible solution is found or not? My first thought was to check the finiteness of the objectivhttps://groups.google.com/d/topic/ampl/hSprxUufuRk
Hamish WatererMon, 23 Feb 2015 08:12:28 UTCround up objective function value
https://groups.google.com/d/msg/ampl/U-GCLziSj9U/BA0unN4WgOMJ
what options allow me to round up the objective function value display? for example I would like to round up the solve output highlighted below to 192000.00 ---------- Begin Solver Output ----------- Job submitted to NEOS HTCondor pool. MINOS 5.51: optimal solution found. 2 iterations, objhttps://groups.google.com/d/topic/ampl/U-GCLziSj9U
Cuong P NguyenSat, 21 Feb 2015 03:03:05 UTCAMPL Mac: solver cplex full version does not work..
https://groups.google.com/d/msg/ampl/_tgPzHJ9rHM/PqTrq1FZSrAJ
Hello everyone, I have just downloaded the full version of AMPL after my student version. But the problem is, the solver cplex of the full version does not work, every time when I tried to run the AMPL IDE, I received this message : CPLEX http://12.5.1.0: error running cplex: termination code 11https://groups.google.com/d/topic/ampl/_tgPzHJ9rHM
m...@animest.netFri, 20 Feb 2015 17:58:20 UTCSQL INSERT/DELETE statements from AMPL
https://groups.google.com/d/msg/ampl/Mhs0luzQrlY/BESb4MosYhYJ
Hello, is there some way to do INSERTs and DELETEs to a MySQL database connected via ODBC from AMPL? I can read my data without problems using the table IN with SQL=SELECT ... but the documentation doesn't explain something similar to do INSERTs (or DELETEs which are not that important for me)https://groups.google.com/d/topic/ampl/Mhs0luzQrlY
Stefan LendlThu, 19 Feb 2015 23:47:58 UTCdefining a large upper/lower bound vector for decision variables
https://groups.google.com/d/msg/ampl/QB9soCQbeAs/O6z6_yUea50J
Hello all, I have 2884 decision variables in my problem which have some upper and lower bounds. Since most of the upper and lower bounds are similar, it is better not to define them in a table form. Instead, I have tried to do this in .dat file: param begin := 1; param end := 2884; # inihttps://groups.google.com/d/topic/ampl/QB9soCQbeAs
seyyed ali pourmousaviWed, 18 Feb 2015 18:46:52 UTC