Web Interface

For new users, the web interface is the easiest way to submit jobs to the NEOS Server. To illustrate the process, we show the steps for submitting a GAMS model of a nonlinearly constrained chemical equilibrium optimization problem to the solver KNITRO. The file ChemEq.txt contains the GAMS model of the problem.

Step 1: Select a solver
Go to the list of available solvers by category to select an appropriate solver for your optimization problem.

Step 2: Select the input format
Next to the name of each solver is the list of input types available for the solver; each input type links to a page that contains specific information for the solver-input type combination. Depending on the solver, the input types may be modeling languages (e.g., AMPL, GAMS), programming languages (e.g., C, Fortran) or a solver- or a problem-specific input type (e.g., TSPLIB for TSP, SDPA for semidefinite programming).

For KNITRO, the input types are AMPL and GAMS; when we click on the GAMS link, we are redirected to the information page for KNITRO-GAMS.

Step 3: Prepare and upload files
Prepare the model file along with any other required or desired files (e.g., data file, commands file, etc.) and upload the file(s). Here the ChemEq.txt file contains the model and the commands, so only one file needs to be uploaded. Use the "Browse" button to locate the files on your system. The image below shows that the file chemeq.txt has been uploaded in the "Model File" section.


Step 4: Select options
Here we check the box to request the log file containing information generated by the algorithm during the solve.


Step 5: Submit the job
To submit the job, we enter our email address and click the "Submit to NEOS" button at the bottom of the page.

When the job is submitted, the NEOS Server assigns a job number and a password and displays the list of jobs running and queued, as shown below. Notice that the job submitted is listed in the queue.

Once the appropriate resources are available, the NEOS Server will print a message that the job has been dispatched.

Job 3079860 dispatched
password: kKlYaJqV
---------- Begin Solver Output -----------
Job submitted to NEOS HTCondor pool.
Step 6: Receive the results
If the job only requires a short amount of time, the results will stream and be displayed to the screen. If the job requires a longer amount of time, the results will not stream. For more information about job priorities and output streaming, see the NEOS Server FAQ. If the job was submitted with a valid email address, the results will be sent when the job is completed. Alternatively, the job number and password can be used to view the job queue and the job results on the NEOS job admin page.