ignorance and intolerance in computing communties

[Frank Buss]

Xah Lee wrote:

> I'm still interested, if someone would show the source code, of how
> Perl, Python, or Lisp or Java, implement the function that finds the
> angle of a complex number.

So you have forgotten to cross-post to comp.lang.java :-)

I think at least for strict floating-point Java uses the netlib: 

http://www.netlib.org/fdlibm/e_atan2.c

For normal floating-point calculations I assume Java uses something like
FPATAN on x86'er computers:

http://www.ews.uiuc.edu/~cjiang/reference/vc107.htm

But you can download the source code of the JVM to verify it yourself:

https://openjdk.dev.java.net/

-- 
Frank Buss, fb at frank-buss.de
http://www.frank-buss.de, http://www.it4-systems.de