log( number, base )
Returns the logarithm of the number using the specified base, which is the power that base must be raised to, to equal the number.
Keyword  Type  Description 


Decimal 
A number, the logarithm of which will be returned. 

Decimal 
The base to use in the logarithm calculation. 10 and e are common values for the base. 
Decimal
log(8,2)
returns 3