log10(p1) public

Returns the base 10 logarithm of x.

Domain: (0, INFINITY)

Codomain: (-INFINITY, INFINITY)

Math.log10(1)       #=> 0.0
Math.log10(10)      #=> 1.0
Math.log10(10**100) #=> 100.0
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July 13, 2009
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Any base logarithm

Using basic arithmetic you can get logarithm with any base:

def log_with_base base, num
  Math.log(num) / Math.log(base)
end

Examples:

>> log_with_base 2, 10
=> 3.32192809488736
>> log_with_base 2, 2
=> 1.0
>> log_with_base 2, 4
=> 2.0
>> log_with_base 2, 16
=> 4.0
>> log_with_base 4, 16
=> 2.0