mymodel.mod not found.
File not found: _amplpb.sol
message mean?
Everyone! The NEOS Server is open free to the public. Some of the solvers may limit use, however.
Check out the AMPL FAQ.
We do not offer any of the optimization solvers we let you use through
the Server for download from the Server site. Some of these solvers
are commercial to varying degrees, but we are allowed to offer them
for your use through the Server free-of-charge. To find out more
about them, follow any links on the Web page for the solver, or
do a Web search on the solver or name of the developer. If you
cannot find anything, we may be able to help, but often we know
no more about it than you do.
First, you need to have your optimization problem formulated
in one of the input formats accepted by a solver. Look through
the solvers on the server-solvers
page to see what formats are available for your type of problem.
Most of the solvers have links to pages or Web sites that explain the
syntax of their input format. Once you have your input files ready,
you can go to the Web Form link on the solver page, fill in the
names of your files and any other information, and submit your job
to the Server. Later, you may look at the E-mail option or the
Submission Tool for Unix or Windows (or Macintosh when it
has a good Java runtime environment implementation).
The
NEOS Submission tool
is a high speed, socket-based interface for
UNIX workstations that
provides easy access to all the optimization solvers
available with the NEOS Server.
This tool allows users to submit problems to the NEOS Server
directly from their local networks.
Results are displayed on the screen.
Yes! NEOS does not allow you to compress your entire submission, but if you want to compress the files individually (to accommodate large data files, for example), you can submit them via the Web or Submission Tool interfaces.
The NEOS Server checks each file to see whether it is compressed, so you can compress any data for which the interface has a Browse option. The compression types the Server supports are standard deflation for
At the bottom of the list of solvers are the Administrative solvers.
Kill Job is the one you are looking for, but you will need your job
number and password.
From the main Server Web page, click on the check progress link.
First of all, always give your email address so that the results can be sent to you more reliably. Sometimes when the execution takes a long time without producing any output, the Web server will cause the CGI script to time out. If you save the job password and number and enter them in the admin form, it will give you intermediate or final results. If more than one day has passed since the job finished, however, the file with your results may have been deleted. Again, always give your email address for results forwarding.
Do not try to include your model or data files by name in the AMPL
commands. The files are given new names under NEOS and will be loaded
automatically.
For security reasons, we don’t allow submissions to read or create files after they have been received by NEOS. There are alternatives that can achieve a similar effect, however.
If you have your own copy of the GAMS or AMPL modeling language software, then you can use GAMS or AMPL to read your files locally, before sending your problem to NEOS. Also you can have the results returned to your local GAMS or AMPL environment, wehre you can write whatever files you need. See the description of the Kestrel client for an explanation of how this works.
To transfer information between local text files and NEOS, you can also use the NEOS XML-RPC interface. If you have Python installed (see the Python download instructions) then you can write simple programs to make the transfers. Here’s an example of a program for writing NEOS’s text output to a file:
You have to specifically ask the solver for the values of decision variables. This is done in different ways for different input forms and solvers, so you’ll have to consult the relevant NEOS solver documentation for specifics.
If you are using an AMPL solver that accepts “commands” files, submit a file that contains a “solve” command followed by commands that display results. For example, use the following commands file to create a table of all variables with their lower bounds, optimal values, and upper bounds:
A message such as
Web servers place restrictions of the amount of data that can be uploaded. You should not have this problem if you use email or the Submission Tool. Some of the solvers have limits on the amount of data they can process, though.
Congratulations, you got the format for the
submission correct, and it was passed on to the solver. Usually a runtime
error means that the solver found a syntax error or a floating point
exception like an overflow or a subscript out of bounds. This type of error
should be detected by the solver, which will give an error message about the
problem.
We would appreciate hearing about it when the solver dies without any
message. Please send an email to the solver administrator via the
neos-comments screen for the solver page, mentioning the job number,
the submission interface you were using, and including the submission itself.
Check that the file you sent in contained no non-ASCII formatting
symbols from a composer such as Word or Word Perfect. By saving
your documents as
Some solvers have hard limits on the number of iterations they allow. In those cases, you will receive the results in terms of the best solution found in that number of iterations. The server has an automatic timeout set to 8 hours for linear and nonlinear optimization problems and 48 hours for problems with integer variables. If your problem takes longer than this amount of time on the solver, then you will not receive a result. Note that the administrator for each individual solver can change these limits.
For Web submissions, the maximum number of bytes that may be submitted is currently 1048576. The limit for email submissions is set by our mail server, which may change without our knowledge. The Submission Tool has no hard-wired limit, but the NEOS Server will not send a job larger than 16777216bytes to any solver station.
If you have not received any response from the server within a reasonable amount of time (reasonable defined in terms of how fast your mail generally arrives), you probably will not. The NEOS Server should send you an immediate message upon receipt of your job request telling you the number of that request. Failure is often attributed to one of these causes:
Extra text at the top of your email is harder to avoid with certain mailers and causes the server more problems. One known occasion when some mailers will pre-append information is when you "insert" a file rather than pasting the contents.
The NEOS server was not designed with the capabilities of a mail server, and the fact that it must use, and not merely display, email data limits the formats it can accept. If the first line cannot be parsed correctly, you should receive mail from the server with the offending line and the entire message below. There have been times, however, when the server could not respond to an email message at all. I suggest submitting a small test problem to see if the server can understand your mailer. You may choose one of the sample files on a "Sample Submission" page to send. They usually run only a few minutes.
You may need to refresh the NEOS pages in your browser. We are not above moving things around and have no way to give notice to people not on the neos-news mailing list. Also, solver administrators may choose to disable their solvers at any time without notice.
This is often XPRESS' way of failing when it cannot find a feasible
solution. It could at any time be completely dying for some other reason,
but in our experience an inability to find a feasible point is almost
always the cause for something like the following.
Not necessarily. We've had problems like this in the past when the user data contained lines with only TAB characters in them. Try to make sure none of your files contain TABs, which can be added automatically by your editor. A strange fix, but it's worked before.
Your Fortran objective function can call other subroutines, but if the solver you are using indicates only one file, then the subroutines must all be located in that one file.
Citing the first three works below should cover it.
The paper by J. Czyzyk, M. Mesnier, and J. Moré,
The NEOS Server,
which appeared in
IEEE Journal on Computational Science and Engineering,
5 (1998), pages 68-75,
discusses the design and implementation of the NEOS Server.
The paper by W. Gropp and J. Moré,
Optimization Environments and the NEOS Server,
that appeared in Approximation Theory and Optimization,
M. D. Buhmann and A. Iserles, eds., pages 167-182,
Cambridge University Press, 1997,
discusses the NEOS Server as a problem-solving
environment that simplifies the formulation of
optimization problems and the access to computational resources.
The technical report by E. Dolan,
The NEOS Server 4.0 Administrative Guide,
Technical Memorandum ANL/MCS-TM-250,
Mathematics and Computer Science Division,
Argonne National Laboratory,
May 2001
discusses the Server implementation and use in detail. The
paper is available for download in
compressed postscript format.
The paper by M. Ferris, M. Mesnier, and J. Moré,
NEOS and Condor: Solving optimization problems over the Internet,
discusses the use of Condor,
a distributed resource management system, as a provider
of computational resources for NEOS.
You can download the paper in a
compressed postscript format.
The paper by E.D. Dolan, R. Fourer,J.J. Moré, and T.S. Munson
The NEOS Server: Version 4 and Beyond
takes a look at advances in the server in 2001, including the Kestrel
interface. You can download the paper in
PDF format.
The technical report by E.D. Dolan and T.S. Munson offers a user's
guide to the Kestrel interface.You can download it in Postscript or
PDF format.
The article by E.D. Dolan, J.-P. Goux, R. Fourer, T.S. Munson, and J. Sarich
Kestrel: An Interface from Optimization Modeling Systems to the NEOS Server, to
appear in INFORMS Journal on Computing, (published online ahead of print July 7, 2008) gives details of the design and use of the Kestrel interface to the server.
We are currently using
ADIFOR
for Fortran programs, and
ADOLC
and
ADIC
for C programs. Consult
A Collection of Automatic Differentiation Tools
for additional information on automatic differentiation tools.
The first step is to contact us by sending email to neos-comments@mcs.anl.gov. We are interested in adding solvers that add new capabilities to the Server. The process for adding solvers is described in the NEOS Solvers Documentation.
.gz,.z,.zip, and .Z files.
mymodel.mod not found.
----------------- getresults.py -----------------
#!/usr/bin/env python
# usage: getresults.py jobnumber password outputfile import sys import xmlrpclib
neos = xmlrpclib.ServerProxy("http://neos.mcs.anl.gov:3332")
jobNumber = int(sys.argv[1])
password = sys.argv[2]
outfile = sys.argv[3]
status = neos.getJobStatus(jobNumber,password)
if status == "Bad Password":
sys.stdout.write("Bad password\n")
sys.exit(1)
if status != "Done":
sys.stdout.write("Job %d not done yet\n" % jobNumber)
sys.exit(1)
out = open("outfile","w")
results = neos.getFinalResults(jobNumber,password).data
out.write(results)
out.close()
solve;
display _varname, _var.lb, _var, _var.ub;
A commands file like the following can display selected variables and more general expressions:
solve;
display Crews, Hire, Layoff;
display {t in time} (rtr * sl * dpp[t] * cs * Crews[t],
hc[t] * Hire[t], lc[t] * Layoff[t]);
unicode decode error, ordinal not in range (128)
or
UnicodeDecodeError: 'ascii' codec can't decode
byte 0x96 in position 12846: ordinal not in range(128)
implies that your input to NEOS contained character codes outside of the standard range of ASCII codes. For example, your input may contain codes for accented characters, or Greek letters, or mathematical symbols. You will need to delete or replace these characters, and resubmit your file. If it’s not obvious where the characters are in the file, try saving it as a text file or opening and saving it in a plain-text editor.
.txt files, you should be able to
get rid of the formatting symbols.
File not found: _amplpb.sol
message mean?
XPRESS-MP 12.13: maxtim=7000
Error preparing solution file
? 85 Error: File not found: _amplpb.sol
?122 Error: Corrupt Solution file.
exit code 1
