Class: Math

Inherits:
Object show all
Defined in:
lib/backports/1.9.1/math/log.rb

Class Method Summary collapse

Class Method Details

.log2(numeric) ⇒ Object 



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# File 'lib/backports/1.9.1/math/log2.rb', line 2

def Math.log2(numeric)
  log(numeric) / log(2)
end

.log_with_optional_base(numeric, base = Backports::Undefined) ⇒ Object

Standard in Ruby 1.9. See official documentation



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# File 'lib/backports/1.9.1/math/log.rb', line 7

def log_with_optional_base(numeric, base = Backports::Undefined)
  if base.equal?(Backports::Undefined)
    # Math.log(n) in 1.9.1 no longer accepts string arguments as it
    # did on 1.8.x, but we won't risk redefining existing behavior
    # when called with just one argument.
    log_without_optional_base(numeric)
  else
    # Math.log(n, b) in 1.9.1 does not accept string arguments:
    raise TypeError, "can't convert String into Float" if numeric.is_a?(String) || base.is_a?(String)
    log_without_optional_base(numeric) / log_without_optional_base(base)
  end
end