July 2016
Beginner to intermediate
462 pages
9h 14m
English
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Speeding up numerical expressions with Numexpr
Numexpr is a software package for the evaluation of numerical array expressions, which is also installed when you install pandas, and you may have seen it announced in the watermark of other recipes (tested with Numexpr 2.3.1). Numexpr tries to speed up calculations by avoiding the creation of temporary variables because reading the variables can be a potential bottleneck. The largest speedups are expected for arrays that can't fit in the CPU cache.
Numexpr splits large arrays into chunks, which fit in the cache, and it also uses multiple cores in parallel when possible. It has an evaluate() function, which accepts simple expressions and evaluates them (refer to the documentation for the complete list ...