# Complexity of Cooley Tukey FFT

http://www.jstor.org/stable/2003354?seq=5#page_scan_tab_contents

In the original algorithm of Cooley Tukey it says that in page 298 (11) and (12) the total number of operations is T(r) = rNlogN/logr.

But in many books and references it says NlogN only. What is the difference here?

• hsm.stackexchange.com might be a better candidate. This is not really about mathematics. – copper.hat Dec 6 '17 at 18:07
• What is $r$ ? Usually the complexity of the FFT is the number of multiplications+additions of a certain precision. – reuns Dec 7 '17 at 13:55
• r is the radix, here it can be 2 – Hüseyin Kömürcü Dec 7 '17 at 16:17