The user base for CVX has grown to such an extent that we can no longer provide direct support for most CVX usage issues without a paid support contract. Instead we have created and identified a number of alternative avenues for support.
The users’ guide and example library
Included with the CVX package are PDF and HTML versions of our extensive users’ guide. The guide includes installation instructions, a quickstart tutorial, a list of the disciplined convex programming rules that govern model construction, and a function reference. We have placed it online and made it searchable in order to help you find the answers to your questions.
The example library is available for browsing online and is included with the CVX package as well. The models contained therein are public domain, so feel free to use these examples as templates for your own projects.
The CVX Forum
For CVX-specific issues that are not caused by bugs in CVX, we invite you to post your question on the CVX Forum. This is a community-driven Q&A site that allows our users to not only submit questions and to answer other people’s questions as well, using a format similar to the well-known Stack Exchange family of sites. We highly encourage our expert users who enjoy helping others to participate in this forum. We hope that it will not only serve as a resource for diagnosing problems and issues, but a clearinghouse for advanced usage tips and tricks.
Computational Science StackExchange
The Computational Science Stack Exchange (SciComp) is a great community-driven Q&A site for a variety of computational science topics, including convex optimization and mixed-integer problems. This would be a perfect choice for questions that are not necessarily specific to CVX. A number of convex optimization experts regularly contribute to this forum, including one of the authors of CVX.
OR Exchange is another Q&A site sponsored by INFORMS, an international society for professionals in operations research, management science, and analytics. There is currently more CVX-related discussion on SciComp than on OR Exchange, but both are helpful resources for optimization questions.
Submitting bug reports
For bugs, installation or licensing issues, or documentation errors, please visit the CVX Research help desk and click the “Submit a ticket” button, or send an email to CVX Support (firstname.lastname@example.org). In either case, please include the following in your bug report so we can fully reproduce the problem:
- the CVX model and supporting data that caused the error.
- a copy of any error messages that it produced
- the CVX version number and build number
- the version number of Matlab that you are running
- the name and version of the operating system you are using
The easiest way to supply items 3-5 is to type cvx_version at the command prompt and copy its output into your email message.
What is a bug?
With a package like CVX that encapsulates such mathematical complexity, it can sometimes be unclear if a problem with a model is due to model formulation or a bug in CVX. The section in the users’ guide entitled What is a bug? was created to help you discern the difference—and to determine the most appropriate channel for support.
The section Handling numerical issues provides some practical advice when you face issues caused by the finite numerical precision of the underlying numerical solvers.
Both the CVX Forum and our trouble-ticket bug report system are funded by CVX Professional license fees. Paid subscribers are provide with pre-created accounts on our support portal, and their trouble tickets are automatically accelerated.
If you are interested in engaging CVX Research, Inc. in a contract for consultation, model implementation, training, or custom implementation, please contact us.