topic c++ std::nth_element-like sorting in IPP? in Intel® Integrated Performance Primitives

c++ std::nth_element-like sorting in IPP?

Duane_R_ — Mon, 04 Apr 2016 14:15:27 GMT

Does IPP contain a method for computing 'partially sorted' data? In particular, I'm looking for something comparable to the std::nth_element method in C++ that guarantees that data elements less than the element value at n reside at indices less than n, and those that are greater than the value at n reside at indices greater than n, but with no sorting guaranteed for indices i<n guaranteed (and, of course, none for i>n). Thanks in advance for your help.

Hi,

Chao_Y_Intel — Fri, 08 Apr 2016 02:16:04 GMT

Hi,

Thanks for checking this. Intel IPP does not include this function now. I may track it in our feature request database, so it can be reviewed when we plan the future release. Where will such function be helpful?

Regards,
Chao

In the sequential setting

Andreas_Fabri__Geome — Thu, 18 May 2017 13:56:29 GMT

In the sequential setting finding the nth_element takes linear time, whereas sorting takes N log N time, so maybe a parallel nth_element is also faster than a parallel sort.