Log

Returns the natural logarithm of a given number

Syntax
   Declare Function Log cdecl ( ByVal number As Double ) As Double

Usage
   result = Log( number )

Parameters
   number
      The number to calculate the natural log.

Return Value
   Returns the logarithm with the base e (also know as the natural 
   logarithm) of number.

Description
   There can be some confusion with this notation given that in mathematics 
   the natural logarithm function is usually denoted LN, while the 
   logarithm of base 10 is often denoted as LOG. FreeBASIC, like most 
   computer programming languages, uses LOG to denote the natural 
   logarithm. The required number argument can be any valid numeric 
   expression greater than zero. If number is zero, FreeBASIC returns a 
   special value representing "-infinity", printing like "-Inf". If number 
   is less than zero, Log returns a special value representing "not 
   defined", printing like "NaN" or "IND", exact text is platform 
   dependent. If number is an uninitialized variable, -infinity is 
   returned.

   Log can be overloaded as operator to accept user-defined types.

Example
   'Find the logarithm of any base
   Function LogBaseX (ByVal Number As Double, ByVal BaseX As Double) As Double
      LogBaseX = Log( Number ) / Log( BaseX )
      'For reference:   1/log(10)=0.43429448
   End Function

   Print "The log base 10 of 20 is:"; LogBaseX ( 20 , 10 )
   Print "The log base 2 of 16 is:"; LogBaseX ( 16 , 2 )

   Sleep

The output would look like:

   The Log Base 10 of 20 Is: 1.301029995663981
   The Log Base 2 of 16 Is: 4

Differences from QB
   * None

See also
   * Exp

