Intel® Math Kernel Library 2019 Developer Guide

Managing Behavior of Function Domains with Environment Variables

NaN checking on matrix input can be expensive. By default, NaN checking is turned on. LAPACKE provides a way to set it through the environment variable:

The other way is to call the LAPACKE_set_nancheck flag; see the Developer Reference for C's Support Functions section for more information.

Note that the NaN-checking flag value set by the call to LAPACKE_set_nancheck will always have higher priority than the environment variable LAPACKE_NANCHECK.