# Google Group Mirror **URL:** https://discuss.ampl.com/c/google-group/44.md?page=5 [Latest](https://discuss.ampl.com/latest.md) · [Categories](https://discuss.ampl.com/categories.md) · [Tags](https://discuss.ampl.com/tags.md) **Page:** 6 --- ## [\[AMPL 24625\] Bootstrap Method](https://discuss.ampl.com/t/ampl-24625-bootstrap-method/529)
**Author:** [@qazawaxaeaca123a](https://discuss.ampl.com/u/qazawaxaeaca123a)\ **Replies:** 0\ **Last updated:** [April 30, 2023, 4:33am UTC](https://discuss.ampl.com/t/ampl-24625-bootstrap-method/529 "2023-04-30T04:33:30Z")
Dear AMPL teams, I am currently conducting an experiment that requires the use of the “Bootstrap Method” technique. Despite consulting the instruction manual and various online forums, I have not been able to find any i… --- ## [\[AMPL 24624\] FW: Last Call: Optimization Modeling session @ fall INFORMS](https://discuss.ampl.com/t/ampl-24624-fw-last-call-optimization-modeling-session-fall-informs/521)
**Author:** [@AMPL\_Google\_Group](https://discuss.ampl.com/u/AMPL_Google_Group)\ **Replies:** 0\ **Last updated:** [April 28, 2023, 4:57pm UTC](https://discuss.ampl.com/t/ampl-24624-fw-last-call-optimization-modeling-session-fall-informs/521 "2023-04-28T16:57:44Z")
LAST CALL! Optimization Modeling Software session INFORMS Annual Meeting, October 15-18, 2023 Deadline for speaker names: Tuesday, May 2 Deadline for abstracts: Tuesday, May 16 To participate in this session, you ne… --- ## [\[AMPL 24621\] information about branch and bound with Gurobi in AMPL](https://discuss.ampl.com/t/ampl-24621-information-about-branch-and-bound-with-gurobi-in-ampl/516)
**Author:** [@Alessandro\_Rosati](https://discuss.ampl.com/u/Alessandro_Rosati)\ **Replies:** 1\ **Last updated:** [April 25, 2023, 6:37pm UTC](https://discuss.ampl.com/t/ampl-24621-information-about-branch-and-bound-with-gurobi-in-ampl/516 "2023-04-25T18:37:03Z")
Where i find the information about branch and bound in AMPL with solver Gurobi. In particulare these informations are : maximum cardinality Clique, dual bound release continuous , number of nodes branch and bound, numbe… --- ## [\[AMPL 24620\] change the solver using loop](https://discuss.ampl.com/t/ampl-24620-change-the-solver-using-loop/514)
**Author:** [@sd1](https://discuss.ampl.com/u/sd1)\ **Replies:** 1\ **Last updated:** [April 24, 2023, 5:06pm UTC](https://discuss.ampl.com/t/ampl-24620-change-the-solver-using-loop/514 "2023-04-24T17:06:11Z")
Hope all is well. I want to compare the performance of a lot of different solvers in ampl so I tried these commands in the console. However, it did not work. Is there any other way to avoid setting up the solver repeate… --- ## [\[AMPL 24616\] AMPL Inquiries](https://discuss.ampl.com/t/ampl-24616-ampl-inquiries/506)
**Author:** [@AMPL\_Google\_Group](https://discuss.ampl.com/u/AMPL_Google_Group)\ **Replies:** 1\ **Last updated:** [April 19, 2023, 4:04pm UTC](https://discuss.ampl.com/t/ampl-24616-ampl-inquiries/506 "2023-04-19T16:04:44Z")
Dear AMPL customer servicer： Hello!I have some questions about AMPL I would like to ask you.My research problem is the problem of assembly shop scheduling.But I had trouble building models with AMPL.Here are my question… --- ## [\[AMPL 24618\] AMPL Inquiries](https://discuss.ampl.com/t/ampl-24618-ampl-inquiries/508)
**Author:** [@18845789723](https://discuss.ampl.com/u/18845789723)\ **Replies:** 0\ **Last updated:** [April 19, 2023, 4:41am UTC](https://discuss.ampl.com/t/ampl-24618-ampl-inquiries/508 "2023-04-19T04:41:15Z")
Dear AMPL customer servicer： Hello!I have some questions about AMPL I would like to ask you.My research problem is the problem of assembly shop scheduling.But I had trouble building models with AMPL.Here are my question… --- ## [\[AMPL 24614\] Unbounded out](https://discuss.ampl.com/t/ampl-24614-unbounded-out/501)
**Author:** [@Davids\_David2](https://discuss.ampl.com/u/Davids_David2)\ **Replies:** 1\ **Last updated:** [April 18, 2023, 6:09pm UTC](https://discuss.ampl.com/t/ampl-24614-unbounded-out/501 "2023-04-18T18:09:22Z")
Hello Sir, Could you please help me check what is the error in my optimization model? The solver displays the output such as: ampl: reset; ampl: model Practicemodel.mod; ampl: data Practicemodel.dat; ampl: option so… --- ## [\[AMPL 24616\] SOS1](https://discuss.ampl.com/t/ampl-24616-sos1/505)
**Author:** [@Manuel\_Alvarez\_Rodri](https://discuss.ampl.com/u/Manuel_Alvarez_Rodri)\ **Replies:** 1\ **Last updated:** [April 18, 2023, 6:05pm UTC](https://discuss.ampl.com/t/ampl-24616-sos1/505 "2023-04-18T18:05:03Z")
Hello, I have a variable x with indexes l in LOCATIONS and t in TYPES. It is possible, following the notation “var x {LOCATIONS} in CAPACITIES;”, to define for each t in TYPES, X{LOCATIONS, t} in a different set that de… --- ## [\[AMPL 24615\] SOS1](https://discuss.ampl.com/t/ampl-24615-sos1/504)
**Author:** [@Manuel\_Alvarez\_Rodri](https://discuss.ampl.com/u/Manuel_Alvarez_Rodri)\ **Replies:** 1\ **Last updated:** [April 18, 2023, 6:04pm UTC](https://discuss.ampl.com/t/ampl-24615-sos1/504 "2023-04-18T18:04:50Z")
Hello, I have a variable x with indexs l in LOCATIONS and t in TYPES. It is possible, following the notation “var x {LOCATIONS} in CAPACITIES;”, to define for each t in TYPES, X{LOCATIONS, t} in a different set that dep… --- ## [\[AMPL 24613\] Declaring constraint without defining it](https://discuss.ampl.com/t/ampl-24613-declaring-constraint-without-defining-it/496)
**Author:** [@Akshay](https://discuss.ampl.com/u/Akshay)\ **Replies:** 1\ **Last updated:** [April 16, 2023, 6:30pm UTC](https://discuss.ampl.com/t/ampl-24613-declaring-constraint-without-defining-it/496 "2023-04-16T18:30:50Z")
Hello, Is there a way to declare a collection of constraints in the model file but not necessarily define it until after the data has been loaded? This is mostly relevant for nonlinear programs where I would need to ch… --- ## [\[AMPL 24611\] ‼️Urgent assist limit time ‼️](https://discuss.ampl.com/t/ampl-24611-urgent-assist-limit-time/492)
**Author:** [@Maha\_Alruwaili](https://discuss.ampl.com/u/Maha_Alruwaili)\ **Replies:** 0\ **Last updated:** [April 12, 2023, 3:07pm UTC](https://discuss.ampl.com/t/ampl-24611-urgent-assist-limit-time/492 "2023-04-12T15:07:15Z")
Dear l hope you are well l would like urgent assistance with the License as lam still student at university of Leeds and working in ampl optimisation l needs to open my module please l get this message here Please… --- ## [\[AMPL 24609\] Sets/Parameters Declaration](https://discuss.ampl.com/t/ampl-24609-sets-parameters-declaration/488)
**Author:** [@John\_Matovu](https://discuss.ampl.com/u/John_Matovu)\ **Replies:** 2\ **Last updated:** [April 11, 2023, 4:44pm UTC](https://discuss.ampl.com/t/ampl-24609-sets-parameters-declaration/488 "2023-04-11T16:44:36Z")
Is there a way of grouping all sets using one word Instead of: set A; set B; set C; I only want to use the word set once like: set A,B,C; This also applies to parameters or variables declaration. It becomes very r… --- ## [\[AMPL 24604\] AMPL duplicate member "x" for set "y", how to fix it](https://discuss.ampl.com/t/ampl-24604-ampl-duplicate-member-x-for-set-y-how-to-fix-it/477)
**Author:** [@Ares\_Inglada\_Grano](https://discuss.ampl.com/u/Ares_Inglada_Grano)\ **Replies:** 1\ **Last updated:** [April 6, 2023, 9:24pm UTC](https://discuss.ampl.com/t/ampl-24604-ampl-duplicate-member-x-for-set-y-how-to-fix-it/477 "2023-04-06T21:24:07Z")
I’m working with AMPL. In the “.mod” I have declared a set like this: set path\_intersections; It consists of rows of two numbers, the first one is the number of the path, and the second one the number of the intersection… --- ## [\[AMPL 24606\] Index problem](https://discuss.ampl.com/t/ampl-24606-index-problem/480)
**Author:** [@Ares\_Inglada\_Grano](https://discuss.ampl.com/u/Ares_Inglada_Grano)\ **Replies:** 1\ **Last updated:** [April 6, 2023, 6:17pm UTC](https://discuss.ampl.com/t/ampl-24606-index-problem/480 "2023-04-06T18:17:00Z")
I have this code in .mod: # Sets set paths; set intersections; set fixed; set prohibited; set path\_intersections dimen 2; # Params param path\_flow {paths} \>= 0; # Variables de decision var x{intersections} binary; var… --- ## [\[AMPL 24598\] variable in lower bound of range set](https://discuss.ampl.com/t/ampl-24598-variable-in-lower-bound-of-range-set/469)
**Author:** [@Liu\_Fan](https://discuss.ampl.com/u/Liu_Fan)\ **Replies:** 3\ **Last updated:** [April 5, 2023, 6:27am UTC](https://discuss.ampl.com/t/ampl-24598-variable-in-lower-bound-of-range-set/469 "2023-04-05T06:27:24Z")
Dear AII, I hope this email finds you well. I am writing to ask for your help with a problem I am facing in my work. Specifically, I am having trouble with the variable in the lower bound of a range set problem. The sp… --- ## [\[AMPL 24601\] Re: Double summation](https://discuss.ampl.com/t/ampl-24601-re-double-summation/470)
**Author:** [@Ruonan\_Zhao](https://discuss.ampl.com/u/Ruonan_Zhao)\ **Replies:** 2\ **Last updated:** [April 5, 2023, 2:20am UTC](https://discuss.ampl.com/t/ampl-24601-re-double-summation/470 "2023-04-05T02:20:54Z")
Hi all, Can anyone please kindly help below. I need to do double summation but index l should not equal to k. Below is what I write but seems wrong. Do you have any suggestions? Thanks! sum {k in K,l in K diff {k}} y\[k… --- ## [\[AMPL 24593\] Differences solver times and real time](https://discuss.ampl.com/t/ampl-24593-differences-solver-times-and-real-time/452)
**Author:** [@Jhoan\_Duque](https://discuss.ampl.com/u/Jhoan_Duque)\ **Replies:** 3\ **Last updated:** [April 3, 2023, 5:58pm UTC](https://discuss.ampl.com/t/ampl-24593-differences-solver-times-and-real-time/452 "2023-04-03T17:58:08Z")
Hi AMPL teams, I am using visual studio community 2022 with API of AMPL for C++ to solve large instances of MIP problems. when calculating the solution time of a large problem, I do it with the c++ chrono commands calcu… --- ## [\[AMPL 24594\] need to write a temporal constraint](https://discuss.ampl.com/t/ampl-24594-need-to-write-a-temporal-constraint/453)
**Author:** [@mohamed\_mady](https://discuss.ampl.com/u/mohamed_mady)\ **Replies:** 1\ **Last updated:** [March 27, 2023, 5:28pm UTC](https://discuss.ampl.com/t/ampl-24594-need-to-write-a-temporal-constraint/453 "2023-03-27T17:28:18Z")
Hi all, I have some troubling with the following problem: I have a set of aircraft and i need to construct intervals which contains the overlapped aircraft, such intervals are defined starting from an array like ad:=\[9… --- ## [\[AMPL 24588\] Iterations in sensitivity analysis are not running](https://discuss.ampl.com/t/ampl-24588-iterations-in-sensitivity-analysis-are-not-running/450)
**Author:** [@anshul\_chauhan](https://discuss.ampl.com/u/anshul_chauhan)\ **Replies:** 1\ **Last updated:** [March 23, 2023, 6:20pm UTC](https://discuss.ampl.com/t/ampl-24588-iterations-in-sensitivity-analysis-are-not-running/450 "2023-03-23T18:20:02Z")
Hi, I am running a Probability Sensitivity Analysis (PSA) with multiple iterations starting from 10. The values are not reflecting any changes i make in the model. --- ## [\[AMPL 24521\] Call for Presentations: SOFTWARE FOR OPTIMIZATION -- IFORS 2023, Santiago, Chile](https://discuss.ampl.com/t/ampl-24521-call-for-presentations-software-for-optimization-ifors-2023-santiago-chile/364)
**Author:** [@AMPL\_Google\_Group](https://discuss.ampl.com/u/AMPL_Google_Group)\ **Replies:** 1\ **Last updated:** [March 23, 2023, 4:52pm UTC](https://discuss.ampl.com/t/ampl-24521-call-for-presentations-software-for-optimization-ifors-2023-santiago-chile/364 "2023-03-23T16:52:49Z")
I am organizing a cluster of sessions on SOFTWARE FOR OPTIMIZATION at IFORS 2023, the 23rd Conference of the International Federation of Operational Research Societies, to be held in Santiago, Chile, 10-14 July … --- ## [Re: \[AMPL 24588\] AMPL Direct Spreadsheet Interface: Iteration problem](https://discuss.ampl.com/t/re-ampl-24588-ampl-direct-spreadsheet-interface-iteration-problem/451)
**Author:** [@anshul\_chauhan](https://discuss.ampl.com/u/anshul_chauhan)\ **Replies:** 0\ **Last updated:** [March 23, 2023, 9:51am UTC](https://discuss.ampl.com/t/re-ampl-24588-ampl-direct-spreadsheet-interface-iteration-problem/451 "2023-03-23T09:51:47Z")
This is the VBA code Option Explicit Sub runPSA() Dim i As Integer Dim N As Integer N = 10 Range(“Parameters!PSA”).Value = 2 Application.Calculation = xlCalculationManual Application.ScreenUpdating = False For i… --- ## [\[AMPL 24582\] Selcting one value](https://discuss.ampl.com/t/ampl-24582-selcting-one-value/447)
**Author:** [@Davids\_David2](https://discuss.ampl.com/u/Davids_David2)\ **Replies:** 1\ **Last updated:** [March 21, 2023, 5:02pm UTC](https://discuss.ampl.com/t/ampl-24582-selcting-one-value/447 "2023-03-21T17:02:54Z")
Hello sir, I am running an optimization problem with a goal to minimize the operation cost of a shop. I would like to reduce the Pg\_Peak by adding a penalty factor such as C\_peak\*PgPeak. However, I am struggling to writ… --- ## [\[AMPL 24583\] License](https://discuss.ampl.com/t/ampl-24583-license/448)
**Author:** [@Niken\_Nurfauziah](https://discuss.ampl.com/u/Niken_Nurfauziah)\ **Replies:** 1\ **Last updated:** [March 21, 2023, 3:12pm UTC](https://discuss.ampl.com/t/ampl-24583-license/448 "2023-03-21T15:12:25Z")
I want to complete my research using AMPL and Gurobi. But I can’t run my model because of more than 500 variables and 500 constraints. I have used the Gurobi license with a limit of 2000 variables and 2000 constraints an… --- ## [\[AMPL 24580\] generate a pool with several solutions (not optimal)](https://discuss.ampl.com/t/ampl-24580-generate-a-pool-with-several-solutions-not-optimal/445)
**Author:** [@juan.carlos](https://discuss.ampl.com/u/juan.carlos)\ **Replies:** 0\ **Last updated:** [March 20, 2023, 1:19am UTC](https://discuss.ampl.com/t/ampl-24580-generate-a-pool-with-several-solutions-not-optimal/445 "2023-03-20T01:19:49Z")
Hi, I’m trying to generate a pool with optimal solutions. However, after executing my model for 8 hours, I didn’t find an optimal solution. The solution I found was: absmipgap = 0.036, relmipgap = 0.6 Therefore, I dec… --- ## [\[AMPL 24578\] define set in another set](https://discuss.ampl.com/t/ampl-24578-define-set-in-another-set/442)
**Author:** [@mohamed\_mady](https://discuss.ampl.com/u/mohamed_mady)\ **Replies:** 2\ **Last updated:** [March 19, 2023, 9:41am UTC](https://discuss.ampl.com/t/ampl-24578-define-set-in-another-set/442 "2023-03-19T09:41:25Z")
Hi all, I have a problem regarding defining two sets, in particular: 1- I need to define I\_dt for each t, where inside each I\_dt I need to put a set of flight, for example I\_d1= flight1, flight2, flight3 for t=1, I\_d2=… --- ## [Re: \[AMPL 24576\] run out of memory](https://discuss.ampl.com/t/re-ampl-24576-run-out-of-memory/439)
**Author:** [@Yulieth\_Vanessa\_Palo](https://discuss.ampl.com/u/Yulieth_Vanessa_Palo)\ **Replies:** 1\ **Last updated:** [March 16, 2023, 4:28pm UTC](https://discuss.ampl.com/t/re-ampl-24576-run-out-of-memory/439 "2023-03-16T16:28:28Z")
Hello. Can you give me please the version 12.9 dll cplex --- ## [\[AMPL 24573\] Gurobi options: problem with outlev option for AMPL](https://discuss.ampl.com/t/ampl-24573-gurobi-options-problem-with-outlev-option-for-ampl/438)
**Author:** [@Yelky\_Alberto\_Castro](https://discuss.ampl.com/u/Yelky_Alberto_Castro)\ **Replies:** 1\ **Last updated:** [March 14, 2023, 5:16pm UTC](https://discuss.ampl.com/t/ampl-24573-gurobi-options-problem-with-outlev-option-for-ampl/438 "2023-03-14T17:16:44Z")
I am trying to use the “outlev=1” option and save all the generated information in a log file. But in the end I can’t generate that information. I am going to attach the 3 files corresponding to the model, data set and t… --- ## [\[AMPL 24567\] condition](https://discuss.ampl.com/t/ampl-24567-condition/431)
**Author:** [@Rahaf](https://discuss.ampl.com/u/Rahaf)\ **Replies:** 4\ **Last updated:** [March 14, 2023, 4:51pm UTC](https://discuss.ampl.com/t/ampl-24567-condition/431 "2023-03-14T16:51:34Z")
Hello Could someone help me to solve this issue please, I have 7 devices, each device represents with a letter g, and the device that is neighbor to it represents with a latter gu. Devices 1 to 4 are transmitters, dev… --- ## [\[AMPL 24568\] Emission coefficients](https://discuss.ampl.com/t/ampl-24568-emission-coefficients/434)
**Author:** [@SANTIAGO\_AYABACA\_LAN](https://discuss.ampl.com/u/SANTIAGO_AYABACA_LAN)\ **Replies:** 2\ **Last updated:** [March 13, 2023, 4:50pm UTC](https://discuss.ampl.com/t/ampl-24568-emission-coefficients/434 "2023-03-13T16:50:57Z")
Where can I find the emission coefficients for the IEEE 300 Bus system?. Matpower does not present these coefficients --- ## [\[AMPL 24564\] Options gurobi](https://discuss.ampl.com/t/ampl-24564-options-gurobi/427)
**Author:** [@Yelky\_Alberto\_Castro](https://discuss.ampl.com/u/Yelky_Alberto_Castro)\ **Replies:** 1\ **Last updated:** [March 10, 2023, 5:14pm UTC](https://discuss.ampl.com/t/ampl-24564-options-gurobi/427 "2023-03-10T17:14:55Z")
I’m trying to show in a log file information that ‘outputlev’ generates, but finally it doesn’t show. add a piece of code: [Previous page](https://discuss.ampl.com/c/google-group/44.md?page=4) [Next page](https://discuss.ampl.com/c/google-group/44.md?page=6)