Math Functions
==============

The **vpython** package for installed Python imports the Python *math* module (``from math import *``).

In Web VPython the following math functions are provided:

.. code-block::

	abs(x)
	sqrt(x)
	sin(x)
	cos(x)
	tan(x)
	asin(x)    # arc sine
	acos(x)    # arc cosine
	atan(x)    # arc tangent; -pi/2 to pi/2
	atan2(y,x) # angle whose tangent is y/x; -pi to pi
	sqrt(x)    # square root
	exp(x)     # e to the x
	log(x)     # natural log, base e
	log10(x)   # log base 10
	pow(x,y)   # x to the power y, alternative to x**y notation
	pi         # 3.14159....
	ceil(x)    # round up to nearest integer
	floor(x)   # round down to nearest integer
	sign(x)    # +1 if x > 0, -1 if x < 0, 0 if x == 0
	round(x,N) # round x to nearest integer; optional N decimal places 
	max(x,y,z) # the largest of x,y,z
	min(x,y,z) # the smallest of x,y,z
	random()   # pseudorandom number 0 to 1
	factorial(x)  # x! = x*(x-1)*(x-2)....(1)
	combin(x,y)   # x!/(y!*(x-y)!)
	max(a,b,c,..) # maximum of these
	min(a,b,c,..) # minimum of these
	radians(theta) # converts theta from degrees to radians
	degrees(phi)  # converts phi from degrees to radians
	clock()    # from the Python time module
	msclock()  # time in ms instead of s
	arange()  # the numpy arange() function

Many of these are based on the JavaScript Math functions. 

Although in general it is not possible to import Python modules into Web VPython programs, an exception is the *random* module, which has been transpiled to a JavaScript library.  In Web VPython use the syntax:

``import random as rr``  or	``from random import randint, uniform``.