Module: Flt::Trigonometry

Defined in:
lib/flt/trigonometry.rb

Overview

Trigonometry functions. The angular units used by these functions can be specified with the angle attribute of the context. The accepted values are:

  • :rad for radians

  • :deg for degrees

  • :grad for gradians

These functions are injected in Context objects.

Defined Under Namespace

Modules: Support

Class Attribute Summary collapse

Instance Method Summary collapse

Class Attribute Details

.pi_cache ⇒ Object

Returns the value of attribute pi_cache.



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# File 'lib/flt/trigonometry.rb', line 131

def pi_cache
  @pi_cache
end

.pi_digits ⇒ Object

Returns the value of attribute pi_digits.



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# File 'lib/flt/trigonometry.rb', line 131

def pi_digits
  @pi_digits
end

.pi_value ⇒ Object

Returns the value of attribute pi_value.



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# File 'lib/flt/trigonometry.rb', line 131

def pi_value
  @pi_value
end

Instance Method Details

#acos(x) ⇒ Object

Arc-cosine. The result is in the units specified by the context angle attribute. If the angular units are radians the result is in [-pi/2, pi/2]; it is in [-90,90] in degrees.



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# File 'lib/flt/trigonometry.rb', line 50

def acos(x)
  acos_base(num_class[x])
end

#acosh(x) ⇒ Object

Hyperbolic arccosine



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# File 'lib/flt/trigonometry.rb', line 116

def acosh(x)
  acosh_base(num_class[x])
end

#asin(x) ⇒ Object

Arc-sine. The result is in the units specified by the context angle attribute. If the angular units are radians the result is in [-pi/2, pi/2]; it is in [-90,90] in degrees.



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# File 'lib/flt/trigonometry.rb', line 44

def asin(x)
  asin_base(num_class[x])
end

#asinh(x) ⇒ Object

Hyperbolic arcsine



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# File 'lib/flt/trigonometry.rb', line 111

def asinh(x)
  asinh_base(num_class[x])
end

#atan(x) ⇒ Object

Arc-tangent. The result is in the units specified by the context angle attribute. If the angular units are radians the result is in [-pi/2, pi/2]; it is in [-90,90] in degrees.



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# File 'lib/flt/trigonometry.rb', line 31

def atan(x)
  atan_base(num_class[x])
end

#atan2(y, x) ⇒ Object

Arc-tangent with two arguments (principal value of the argument of the complex number x+i*y). The result is in the units specified by the context angle attribute. If the angular units are radians the result is in [-pi, pi]; it is in [-180,180] in degrees.



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# File 'lib/flt/trigonometry.rb', line 38

def atan2(y, x)
  atan2_base(num_class[y], num_class[x])
end

#atanh(x) ⇒ Object

Hyperbolic arctangent



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# File 'lib/flt/trigonometry.rb', line 121

def atanh(x)
  atanh_base(num_class[x])
end

#cos(x) ⇒ Object

Cosine of an angle given in the units specified by the context angle attribute.



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# File 'lib/flt/trigonometry.rb', line 15

def cos(x)
  cos_base(num_class[x])
end

#cosh(x) ⇒ Object

Hyperbolic cosine



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# File 'lib/flt/trigonometry.rb', line 101

def cosh(x)
  cosh_base(num_class[x])
end

#e(digits = nil) ⇒ Object 



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# File 'lib/flt/trigonometry.rb', line 84

def e(digits=nil)
  num_class.context(self) do |local_context|
    local_context.precision = digits if digits
    num_class.Num(1).exp
  end
end

#half ⇒ Object 



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# File 'lib/flt/trigonometry.rb', line 91

def half
  @half ||= num_class.one_half
end

#hypot(x, y) ⇒ Object

Length of the hypotenuse of a right-angle triangle (modulus or absolute value of the complex x+i*y).



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# File 'lib/flt/trigonometry.rb', line 55

def hypot(x, y)
  hypot_base(num_class[x], num_class[y])
end

#pi(round_digits = nil) ⇒ Object

Pi



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# File 'lib/flt/trigonometry.rb', line 60

def pi(round_digits=nil)
  round_digits ||= self.precision
  if Trigonometry.pi_digits < round_digits
    # provisional implementation (very slow)
    lasts = 0
    t, s, n, na, d, da = Trigonometry.pi_cache
    num_class.context(self) do |local_context|
      local_context.precision = round_digits + 6
      tol = Rational(1,num_class.int_radix_power(local_context.precision+1))
      while (s-lasts)>tol
        lasts = s
        n, na = n+na, na+8
        d, da = d+da, da+32
        t = (t * n) / d
        s += t
      end
      Trigonometry.pi_value = num_class[s]
      Trigonometry.pi_digits = round_digits
      Trigonometry.pi_cache = [t, s, n, na, d, da]
    end
  end
  num_class.context(self, :precision=>round_digits){+Trigonometry.pi_value}
end

#sin(x) ⇒ Object

Sine of an angle given in the units specified by the context angle attribute.



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# File 'lib/flt/trigonometry.rb', line 20

def sin(x)
  sin_base(num_class[x])
end

#sinh(x) ⇒ Object

Hyperbolic sine



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# File 'lib/flt/trigonometry.rb', line 96

def sinh(x)
  sinh_base(num_class[x])
end

#tan(x) ⇒ Object

Tangent of an angle given in the units specified by the context angle attribute.



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# File 'lib/flt/trigonometry.rb', line 25

def tan(x)
  tan_base(num_class[x])
end

#tanh(x) ⇒ Object

Hyperbolic tangent



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# File 'lib/flt/trigonometry.rb', line 106

def tanh(x)
  tanh_base(num_class[x])
end