Module: Math

Defined in:
opal/opal/corelib/math.rb

Overview

helpers: type_error backtick_javascript: true

Class Method Summary collapse

Class Method Details

.atan2(y, x) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 105

def atan2(y, x)
  ::Math.checked :atan2, ::Math.float!(y), ::Math.float!(x)
end

.checked(method, *args) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 10

def self.checked(method, *args)
  %x{
    if (isNaN(args[0]) || (args.length == 2 && isNaN(args[1]))) {
      return NaN;
    }

    var result = Math[method].apply(null, args);

    if (isNaN(result)) {
      #{::Kernel.raise DomainError, "Numerical argument is out of domain - \"#{method}\""};
    }

    return result;
  }
end

.float!(value) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 26

def self.float!(value)
  ::Kernel.Float(value)
rescue ::ArgumentError
  ::Kernel.raise `$type_error(value, #{::Float})`
end

.frexp(x) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 113

def frexp(x)
  x = Math.float!(x)

  %x{
    if (isNaN(x)) {
      return [NaN, 0];
    }

    var ex   = Math.floor(Math.log(Math.abs(x)) / Math.log(2)) + 1,
        frac = x / Math.pow(2, ex);

    return [frac, ex];
  }
end

.gamma(n) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 128

def gamma(n)
  n = Math.float!(n)

  %x{
    var i, t, x, value, result, twoN, threeN, fourN, fiveN;

    var G = 4.7421875;

    var P = [
       0.99999999999999709182,
       57.156235665862923517,
      -59.597960355475491248,
       14.136097974741747174,
      -0.49191381609762019978,
       0.33994649984811888699e-4,
       0.46523628927048575665e-4,
      -0.98374475304879564677e-4,
       0.15808870322491248884e-3,
      -0.21026444172410488319e-3,
       0.21743961811521264320e-3,
      -0.16431810653676389022e-3,
       0.84418223983852743293e-4,
      -0.26190838401581408670e-4,
       0.36899182659531622704e-5
    ];


    if (isNaN(n)) {
      return NaN;
    }

    if (n === 0 && 1 / n < 0) {
      return -Infinity;
    }

    if (n === -1 || n === -Infinity) {
      #{::Kernel.raise DomainError, 'Numerical argument is out of domain - "gamma"'};
    }

    if (#{Integer === n}) {
      if (n <= 0) {
        return isFinite(n) ? Infinity : NaN;
      }

      if (n > 171) {
        return Infinity;
      }

      value  = n - 2;
      result = n - 1;

      while (value > 1) {
        result *= value;
        value--;
      }

      if (result == 0) {
        result = 1;
      }

      return result;
    }

    if (n < 0.5) {
      return Math.PI / (Math.sin(Math.PI * n) * #{::Math.gamma(1 - n)});
    }

    if (n >= 171.35) {
      return Infinity;
    }

    if (n > 85.0) {
      twoN   = n * n;
      threeN = twoN * n;
      fourN  = threeN * n;
      fiveN  = fourN * n;

      return Math.sqrt(2 * Math.PI / n) * Math.pow((n / Math.E), n) *
        (1 + 1 / (12 * n) + 1 / (288 * twoN) - 139 / (51840 * threeN) -
        571 / (2488320 * fourN) + 163879 / (209018880 * fiveN) +
        5246819 / (75246796800 * fiveN * n));
    }

    n -= 1;
    x  = P[0];

    for (i = 1; i < P.length; ++i) {
      x += P[i] / (n + i);
    }

    t = n + G + 0.5;

    return Math.sqrt(2 * Math.PI) * Math.pow(t, n + 0.5) * Math.exp(-t) * x;
  }
end

.hypot(x, y) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 109

def hypot(x, y)
  ::Math.checked :hypot, ::Math.float!(x), ::Math.float!(y)
end

.integer!(value) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 32

def self.integer!(value)
  ::Kernel.Integer(value)
rescue ::ArgumentError
  ::Kernel.raise `$type_error(value, #{::Integer})`
end

.ldexp(mantissa, exponent) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 224

def ldexp(mantissa, exponent)
  mantissa = Math.float!(mantissa)
  exponent = Math.integer!(exponent)

  %x{
    if (isNaN(exponent)) {
      #{::Kernel.raise ::RangeError, 'float NaN out of range of integer'};
    }

    return mantissa * Math.pow(2, exponent);
  }
end

.lgamma(n) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 237

def lgamma(n)
  %x{
    if (n == -1) {
      return [Infinity, 1];
    }
    else {
      return [Math.log(Math.abs(#{::Math.gamma(n)})), #{::Math.gamma(n)} < 0 ? -1 : 1];
    }
  }
end

.log(x, base = undefined) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 248

def log(x, base = undefined)
  if ::String === x
    ::Kernel.raise `$type_error(x, #{::Float})`
  end

  if `base == null`
    ::Math.checked :log, ::Math.float!(x)
  else
    if ::String === base
      ::Kernel.raise `$type_error(base, #{::Float})`
    end

    ::Math.checked(:log, ::Math.float!(x)) / ::Math.checked(:log, ::Math.float!(base))
  end
end

.log10(x) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 264

def log10(x)
  if ::String === x
    ::Kernel.raise `$type_error(x, #{::Float})`
  end

  ::Math.checked :log10, ::Math.float!(x)
end

.log2(x) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 272

def log2(x)
  if ::String === x
    ::Kernel.raise `$type_error(x, #{::Float})`
  end

  ::Math.checked :log2, ::Math.float!(x)
end

.tan(x) ⇒ Object 



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# File 'opal/opal/corelib/math.rb', line 280

def tan(x)
  x = ::Math.float!(x)

  if x.infinite?
    return ::Float::NAN
  end

  ::Math.checked :tan, ::Math.float!(x)
end