| FreeMat
    | 
Section: Base Constants
Returns a double (64-bit floating point number) value that represents pi (ratio between the circumference and diameter of a circle...). Typical usage 
y = pi
This value is approximately 3.141592653589793.
The following example demonstrates the use of the pi function.
--> pi
ans = 
    3.1416 
--> cos(pi)
ans = 
 -1