performance regression when programmatically creating a model using add_block

Why do we observe such large difference in the time taken in R20016b to create a large Simulink model using MATLAB scripts (copying 40 existing models block by block, line by line) as compared to R2013b?

Answer 1

[MathWorks Support Team]

Adding many blocks to a Simulink model can be slow, such as when you use add_block in a MATLAB script, or copy and paste many blocks.

To diagnose this problem, use the MATLAB profiler to profile the MATLAB script or the copy-paste operation. In the profiler report, this problem manifests as a disproportionately large number of calls to the function getHarnessList.

This is a bug which was fixed. A  bug report is available <https://www.mathworks.com/support/bugreports/1707278>.

A patch for this bug as well as instructions to install it are provided in the bug report.