|
AMPL Frequently Asked Questions
|
|
1
|
370
|
February 23, 2023
|
|
Why do I get an “invalid subscript discarded” message when I display an AMPL parameter?
|
|
0
|
789
|
December 15, 2021
|
|
Can I get a version of AMPL that will run on my computer, under my computer’s operating system?
|
|
0
|
328
|
December 15, 2021
|
|
What is AMPL (A Mathematical Programming Language)?
|
|
0
|
371
|
December 15, 2021
|
|
How does AMPL compare to spreadsheet optimizers?
|
|
0
|
380
|
December 15, 2021
|
|
How does AMPL compare to other modeling languages and systems?
|
|
0
|
343
|
December 15, 2021
|
|
How can I learn more about AMPL?
|
|
0
|
331
|
December 15, 2021
|
|
How big a problem can AMPL solve?
|
|
0
|
449
|
December 15, 2021
|
|
Can my program call AMPL as a subroutine?
|
|
0
|
296
|
December 15, 2021
|
|
How can I edit my model or data file without leaving the AMPL command environment?
|
|
0
|
331
|
December 15, 2021
|
|
How do I solve a series of different random problems with data drawn from the same distribution?
|
|
0
|
367
|
December 15, 2021
|
|
When does AMPL evaluate the conditions specified in my model’s check statements?
|
|
0
|
298
|
December 15, 2021
|
|
How do I write an “MPS file” for my problem?
|
|
0
|
847
|
December 15, 2021
|
|
Why does AMPL write an MPS file that is different from what I expect?
|
|
0
|
285
|
December 15, 2021
|
|
What are the transformations that AMPL applies to optimization problems?
|
|
0
|
285
|
December 15, 2021
|
|
How can I prevent AMPL from transforming my problem?
|
|
0
|
302
|
December 15, 2021
|
|
Why does AMPL reject my “let” statement with a “… has a := value in the model” message?
|
|
0
|
312
|
December 15, 2021
|
|
What does AMPL mean by “syntax error”? I double-checked the offending statement in the AMPL book, and my syntax is fine
|
|
0
|
668
|
December 15, 2021
|
|
How can I tell whether messages on my screen are coming from AMPL or from the solver?
|
|
0
|
285
|
December 15, 2021
|
|
Why does AMPL appear to “hang” for a long time without accepting any input or producing any output?
|
|
0
|
356
|
December 15, 2021
|
|
Why does AMPL unexpectedly abort in the middle of doing something? I get a short error message, but I can’t find it explained in the AMPL book or in the solver documentation
|
|
0
|
304
|
December 15, 2021
|
|
What should I do if I suspect that there is insufficient memory for my AMPL session?
|
|
0
|
319
|
December 15, 2021
|
|
Why doesn’t AMPL interpret the expression T..1 as I expect?
|
|
0
|
277
|
December 15, 2021
|
|
Why does “set S := 50 .. 70” give me a set of only 3 members?
|
|
0
|
334
|
December 15, 2021
|
|
I have declared “set S” and “param b {S}”. How do I write an AMPL expression for the arg min of b[i] — that is, the s in S such that b[s] equals the minimum of b[i] over al
|
|
0
|
419
|
December 15, 2021
|
|
How can I get AMPL to index over the “power set” consisting of all subsets of a set?
|
|
0
|
472
|
December 15, 2021
|
|
How can I apply AMPL’s ordered-set functions to pairs and higher-dimensional objects?
|
|
0
|
319
|
December 15, 2021
|
|
When I set option substout 1, why doesn’t AMPL make the substitutions that I expect?
|
|
0
|
290
|
December 15, 2021
|
|
Why does AMPL treat my linear program as nonlinear?
|
|
0
|
312
|
December 15, 2021
|
|
When certain variables are fixed, the nonlinear expressions in my model all become linear. Does AMPL consider my model to be linear in this case?
|
|
0
|
281
|
December 15, 2021
|