Add log() and other avr-libc math functions to reference

[per1234]

Moved from arduino/Arduino#264 by @damellis

This is Issue 264 moved from a Google Code project.
Added by 2010-05-25T20:40:09.000Z by dmel...@gmail.com.
Please review that bug for more context and additional comments, but update this bug.

Original labels: Type-Enhancement, Priority-Medium, Component-Docs, Component-Build

Original description

Since they are available and people want to use them.

[per1234]

Note that the original issue also requested that the names be added to keywords.txt so that the Arduino IDE would highlight them. That component of the request has already been done via arduino/Arduino#8167.

That PR provides a list of the possible math functions in the event that it's decided this documentation request should be implemented:
https://github.com/arduino/Arduino/pull/8167/files

I only added the functions/macros which are also defined in the SAMD toolchain. The list of keywords which were avr-libc specific is here:
arduino/Arduino#8167 (comment)

[per1234]

There is an outdated orphan reference page that does document them to some extent here:
https://www.arduino.cc/en/Reference/MathHeader

[per1234]

Related:

• abs() does not work on floats #362
• Documentation of math/round is missing #927