Thursday, January 20, 2022

MIP 2022

Similarly to previous years MOSEK is proud to be one of the sponsors of MIP2022 - Mixed Integer Programming Workshop 2022, taking place May 23–26, 2022 at DIMACS, Rutgers University.

More details at https://www.mixedinteger.org/2022/

Monday, January 10, 2022

Planned end of support for version 8

On 31-may-2022 we will be stopping active support for version 8 which was released back in 2016.

For details of release and support policy see https://www.mosek.com/products/release-policy/

Tuesday, December 14, 2021

Log4j statement

Neither MOSEK nor any of the tools shipped with the MOSEK package make use of Log4j. The MOSEK library is not vulnerable to the Log4j exploit.

Monday, November 8, 2021

Some animals are more equal than others: least-squares vs Euclidean norm

A user recently reached out to MOSEK support because the solver returned an UNKNOWN problem/solution status on their (constrained) Least-squares problem, that was implemented in CVXPY . The solver log looked as shown in the first MOSEK log shown below.

The solution we offered was to minimize the Euclidean norm instead of the sum-of-squares. Theoretically, both models are equivalent; their optimal points are the same. But as a great man once said: in theory, theory and practice are the same. In practice, well... Take a look at the MOSEK log for the problem that minimizes the Euclidean norm (second MOSEK log)

Note the following differences between the two MOSEK logs:

  • The problem status in the norm problem is primal and dual feasible and the solution status is optimal, in contrast to the least-squares problem.
  • The infinity-norm of the solutions in the norm problem are smaller by nearly 5 orders of magnitude compared to the solution of the least-squares problem. This is usually a desirable trait, as explained in the  debugging section of MOSEK docs 
  • The number of iterations taken by the norm problem is far fewer.
  • The objective value of the norm problem is essentially the square root of the least-squares problem (the least-squares problem was not solved to optimality, hence the discrepancy) 
Observe that the solution is only guaranteed to be unique if the objective is strictly convex. The objective function is strictly convex if and only if the A matrix (following  this notation) is of full column-rank. If this is not the case, then the two problems might output different optimal solution vectors (as is the case above), but as Orwell would put it, one of those solutions will be more equal than the other

So, at least for CVXPY-MOSEK users (and MOSEK Fusion users!), we recommend the Euclidean norm in place of the sum-of-squares, wherever possible.

Tuesday, September 14, 2021

Portfolio Optimization Workshop and Cookbook

We are pleased to announce the MOSEK Portfolio Optimization Workshop, a one-day event on the theoretical and practical aspects of portfolio optimization using MOSEK. The workshop takes place at our location in Copenhagen (this is NOT a virtual event(!)) on Thursday, November 18th, 2021. Topics include:

  • An introduction to portfolio optimization using MOSEK
  • Advanced topics in portfolio optimization
  • Tracking error and portfolio construction
  • MOSEK licensing, developments and news.
There will also be ample time for discussions. We provide lunch for the participants. For the full program with abstracts see the poster:


Participation is free and open to all but we would like you to register via this form in order to keep track of numbers.

Announcing the workshop is also an opportunity to present the first version of the MOSEK Portfolio Optimization Coookbook, which provides an introduction to the topic of portfolio optimization and discusses several branches of practical interest from this broad subject illustrated with examples using the MOSEK Fusion API. For more information about this topic, including links to the cookbook and accompanying Python notebooks visit our comprehensive Portfolio Optimization Resource Page.

Friday, August 6, 2021

MOSEK 9.3 is released

We have released MOSEK 9.3. Release notes:

https://docs.mosek.com/9.3/releasenotes/index.html

This version is a direct continuation of 9.2 with no changes to existing interfaces. The new features are:

  • support for Linux on ARM64 (aarch64), including Optimizer API and Fusion API for C/C++,Java,Python,.NET. The interior-point and conic optimizers are single-threaded on that platform.
  • Updated FLEXlm to version 11.18. In particular, floating license users who upgrade clients to MOSEK 9.3 must also upgrade license server binaries (lmgrd) to the ones from the 9.3 MOSEK distribution for compatibility. The new license server is as always backwards compatible.
  • Improved performance when solving many tasks in parallel.

Wednesday, June 23, 2021

MOSEK 9.3 beta, support for linuxaarch64

We have released a beta version of MOSEK 9.3. It is currently only available for download from our website

https://www.mosek.com/downloads/9.3.0/

Release notes:

https://docs.mosek.com/9.3/releasenotes/index.html

This version is a direct continuation of 9.2 with no changes to existing interfaces. The new features are:

  • support for Linux on ARM64 (aarch64), including Optimizer API and Fusion API for C/C++,Java,Python,.NET. The interior-point and conic optimizers are single-threaded on that platform.
  • Updated FLEXlm to version 11.18. In particular, floating license users who upgrade clients to MOSEK 9.3 must also upgrade license server binaries (lmgrd) to the ones from the 9.3 MOSEK distribution for compatibility. The new license server is as always backwards compatible.
  • Improved performance when solving many tasks in parallel.