A Complex object houses a pair of values, given when the object is created as either rectangular coordinates or polar coordinates.

Rectangular Coordinates

The rectangular coordinates of a complex number are called the real and imaginary parts; see Complex number definition.

You can create a Complex object from rectangular coordinates with:

Note that each of the stored parts may be a an instance one of the classes Complex, Float, Integer, or Rational; they may be retrieved:

The corresponding (computed) polar values may be retrieved:

Polar Coordinates

The polar coordinates of a complex number are called the absolute and argument parts; see Complex polar plane.

In this class, the argument part in expressed radians (not degrees).

You can create a Complex object from polar coordinates with:

Note that each of the stored parts may be a an instance one of the classes Complex, Float, Integer, or Rational; they may be retrieved:

The corresponding (computed) rectangular values may be retrieved:

What’s Here

First, what’s elsewhere:

  • Class Complex inherits (directly or indirectly) from classes Numeric and Object.

  • Includes (indirectly) module Comparable.

Here, class Complex has methods for:

Creating Complex Objects

  • ::polar: Returns a new Complex object based on given polar coordinates.

  • ::rect (and its alias ::rectangular): Returns a new Complex object based on given rectangular coordinates.

Querying

  • abs (and its alias magnitude): Returns the absolute value for self.

  • arg (and its aliases angle and phase): Returns the argument (angle) for self in radians.

  • denominator: Returns the denominator of self.

  • finite?: Returns whether both self.real and self.image are finite.

  • hash: Returns the integer hash value for self.

  • imag (and its alias imaginary): Returns the imaginary value for self.

  • infinite?: Returns whether self.real or self.image is infinite.

  • numerator: Returns the numerator of self.

  • polar: Returns the array [self.abs, self.arg].

  • inspect: Returns a string representation of self.

  • real: Returns the real value for self.

  • real?: Returns false; for compatibility with Numeric#real?.

  • rect (and its alias rectangular): Returns the array [self.real, self.imag].

Comparing

  • <=>: Returns whether self is less than, equal to, or greater than the given argument.

  • ==: Returns whether self is equal to the given argument.

Converting

  • rationalize: Returns a Rational object whose value is exactly or approximately equivalent to that of self.real.

  • to_c: Returns self.

  • to_d: Returns the value as a BigDecimal object.

  • to_f: Returns the value of self.real as a Float, if possible.

  • to_i: Returns the value of self.real as an Integer, if possible.

  • to_r: Returns the value of self.real as a Rational, if possible.

  • to_s: Returns a string representation of self.

Performing Complex Arithmetic

  • *: Returns the product of self and the given numeric.

  • **: Returns self raised to power of the given numeric.

  • +: Returns the sum of self and the given numeric.

  • -: Returns the difference of self and the given numeric.

  • -@: Returns the negation of self.

  • /: Returns the quotient of self and the given numeric.

  • abs2: Returns square of the absolute value (magnitude) for self.

  • conj (and its alias conjugate): Returns the conjugate of self.

  • fdiv: Returns Complex.rect(self.real/numeric, self.imag/numeric).

Working with JSON

  • ::json_create: Returns a new Complex object, deserialized from the given serialized hash.

  • as_json: Returns a serialized hash constructed from self.

  • to_json: Returns a JSON string representing self.

These methods are provided by the JSON gem. To make these methods available:

require 'json/add/complex'
Constants

I

Equivalent to Complex.rect(0, 1):

Complex::I # => (0+1i)
Class Methods

See as_json.

Returns a new Complex object formed from the arguments, each of which must be an instance of Numeric, or an instance of one of its subclasses: Complex, Float, Integer, Rational. Argument arg is given in radians; see Polar Coordinates:

Complex.polar(3)        # => (3+0i)
Complex.polar(3, 2.0)   # => (-1.2484405096414273+2.727892280477045i)
Complex.polar(-3, -2.0) # => (1.2484405096414273+2.727892280477045i)

Returns a new Complex object formed from the arguments, each of which must be an instance of Numeric, or an instance of one of its subclasses: Complex, Float, Integer, Rational; see Rectangular Coordinates:

Complex.rect(3)             # => (3+0i)
Complex.rect(3, Math::PI)   # => (3+3.141592653589793i)
Complex.rect(-3, -Math::PI) # => (-3-3.141592653589793i)

Complex.rectangular is an alias for Complex.rect.

Returns a new Complex object formed from the arguments, each of which must be an instance of Numeric, or an instance of one of its subclasses: Complex, Float, Integer, Rational; see Rectangular Coordinates:

Complex.rect(3)             # => (3+0i)
Complex.rect(3, Math::PI)   # => (3+3.141592653589793i)
Complex.rect(-3, -Math::PI) # => (-3-3.141592653589793i)

Complex.rectangular is an alias for Complex.rect.

Instance Methods

Returns the product of self and numeric:

Complex.rect(2, 3)  * Complex.rect(2, 3)  # => (-5+12i)
Complex.rect(900)   * Complex.rect(1)     # => (900+0i)
Complex.rect(-2, 9) * Complex.rect(-9, 2) # => (0-85i)
Complex.rect(9, 8)  * 4                   # => (36+32i)
Complex.rect(20, 9) * 9.8                 # => (196.0+88.2i)

Returns self raised to power numeric:

Complex.rect(0, 1) ** 2            # => (-1+0i)
Complex.rect(-8) ** Rational(1, 3) # => (1.0000000000000002+1.7320508075688772i)

Returns the sum of self and numeric:

Complex.rect(2, 3)  + Complex.rect(2, 3)  # => (4+6i)
Complex.rect(900)   + Complex.rect(1)     # => (901+0i)
Complex.rect(-2, 9) + Complex.rect(-9, 2) # => (-11+11i)
Complex.rect(9, 8)  + 4                   # => (13+8i)
Complex.rect(20, 9) + 9.8                 # => (29.8+9i)

Returns the difference of self and numeric:

Complex.rect(2, 3)  - Complex.rect(2, 3)  # => (0+0i)
Complex.rect(900)   - Complex.rect(1)     # => (899+0i)
Complex.rect(-2, 9) - Complex.rect(-9, 2) # => (7+7i)
Complex.rect(9, 8)  - 4                   # => (5+8i)
Complex.rect(20, 9) - 9.8                 # => (10.2+9i)

Returns the negation of self, which is the negation of each of its parts:

-Complex.rect(1, 2)   # => (-1-2i)
-Complex.rect(-1, -2) # => (1+2i)

Returns the quotient of self and numeric:

Complex.rect(2, 3)  / Complex.rect(2, 3)  # => (1+0i)
Complex.rect(900)   / Complex.rect(1)     # => (900+0i)
Complex.rect(-2, 9) / Complex.rect(-9, 2) # => ((36/85)-(77/85)*i)
Complex.rect(9, 8)  / 4                   # => ((9/4)+2i)
Complex.rect(20, 9) / 9.8                 # => (2.0408163265306123+0.9183673469387754i)

Returns:

  • self.real <=> object.real if both of the following are true:

    • self.imag == 0.

    • object.imag == 0. # Always true if object is numeric but not complex.

  • nil otherwise.

Examples:

Complex.rect(2) <=> 3                  # => -1
Complex.rect(2) <=> 2                  # => 0
Complex.rect(2) <=> 1                  # => 1
Complex.rect(2, 1) <=> 1               # => nil # self.imag not zero.
Complex.rect(1) <=> Complex.rect(1, 1) # => nil # object.imag not zero.
Complex.rect(1) <=> 'Foo'              # => nil # object.imag not defined.

Returns true if self.real == object.real and self.imag == object.imag:

Complex.rect(2, 3)  == Complex.rect(2.0, 3.0) # => true

Returns the absolute value (magnitude) for self; see polar coordinates:

Complex.polar(-1, 0).abs # => 1.0

If self was created with rectangular coordinates, the returned value is computed, and may be inexact:

Complex.rectangular(1, 1).abs # => 1.4142135623730951 # The square root of 2.

Returns square of the absolute value (magnitude) for self; see polar coordinates:

Complex.polar(2, 2).abs2 # => 4.0

If self was created with rectangular coordinates, the returned value is computed, and may be inexact:

Complex.rectangular(1.0/3, 1.0/3).abs2 # => 0.2222222222222222
An alias for

Returns the argument (angle) for self in radians; see polar coordinates:

Complex.polar(3, Math::PI/2).arg  # => 1.57079632679489660

If self was created with rectangular coordinates, the returned value is computed, and may be inexact:

Complex.polar(1, 1.0/3).arg # => 0.33333333333333326

Methods Complex#as_json and Complex.json_create may be used to serialize and deserialize a Complex object; see Marshal.

Method Complex#as_json serializes self, returning a 2-element hash representing self:

require 'json/add/complex'
x = Complex(2).as_json      # => {"json_class"=>"Complex", "r"=>2, "i"=>0}
y = Complex(2.0, 4).as_json # => {"json_class"=>"Complex", "r"=>2.0, "i"=>4}

Method JSON.create deserializes such a hash, returning a Complex object:

Complex.json_create(x) # => (2+0i)
Complex.json_create(y) # => (2.0+4i)

Returns the conjugate of self, Complex.rect(self.imag, self.real):

Complex.rect(1, 2).conj # => (1-2i)

Returns the denominator of self, which is the least common multiple of self.real.denominator and self.imag.denominator:

Complex.rect(Rational(1, 2), Rational(2, 3)).denominator # => 6

Note that n.denominator of a non-rational numeric is 1.

Related: Complex#numerator.

Returns Complex.rect(self.real/numeric, self.imag/numeric):

Complex.rect(11, 22).fdiv(3) # => (3.6666666666666665+7.333333333333333i)

Returns true if both self.real.finite? and self.imag.finite? are true, false otherwise:

Complex.rect(1, 1).finite?               # => true
Complex.rect(Float::INFINITY, 0).finite? # => false

Related: Numeric#finite?, Float#finite?.

Returns the integer hash value for self.

Two Complex objects created from the same values will have the same hash value (and will compare using eql?):

Complex.rect(1, 2).hash == Complex.rect(1, 2).hash # => true

Returns the imaginary value for self:

Complex.rect(7).imag     # => 0
Complex.rect(9, -4).imag # => -4

If self was created with polar coordinates, the returned value is computed, and may be inexact:

Complex.polar(1, Math::PI/4).imag # => 0.7071067811865476 # Square root of 2.

Returns 1 if either self.real.infinite? or self.imag.infinite? is true, nil otherwise:

Complex.rect(Float::INFINITY, 0).infinite? # => 1
Complex.rect(1, 1).infinite?               # => nil

Related: Numeric#infinite?, Float#infinite?.

Returns a string representation of self:

Complex.rect(2).inspect                      # => "(2+0i)"
Complex.rect(-8, 6).inspect                  # => "(-8+6i)"
Complex.rect(0, Rational(1, 2)).inspect      # => "(0+(1/2)*i)"
Complex.rect(0, Float::INFINITY).inspect     # => "(0+Infinity*i)"
Complex.rect(Float::NAN, Float::NAN).inspect # => "(NaN+NaN*i)"
An alias for

Returns the Complex object created from the numerators of the real and imaginary parts of self, after converting each part to the lowest common denominator of the two:

c = Complex.rect(Rational(2, 3), Rational(3, 4)) # => ((2/3)+(3/4)*i)
c.numerator                                      # => (8+9i)

In this example, the lowest common denominator of the two parts is 12; the two converted parts may be thought of as Rational(8, 12) and Rational(9, 12), whose numerators, respectively, are 8 and 9; so the returned value of c.numerator is Complex.rect(8, 9).

Related: Complex#denominator.

An alias for

Returns the array [self.abs, self.arg]:

Complex.polar(1, 2).polar # => [1.0, 2.0]

See Polar Coordinates.

If self was created with rectangular coordinates, the returned value is computed, and may be inexact:

Complex.rect(1, 1).polar # => [1.4142135623730951, 0.7853981633974483]

Returns the quotient of self and numeric:

Complex.rect(2, 3)  / Complex.rect(2, 3)  # => (1+0i)
Complex.rect(900)   / Complex.rect(1)     # => (900+0i)
Complex.rect(-2, 9) / Complex.rect(-9, 2) # => ((36/85)-(77/85)*i)
Complex.rect(9, 8)  / 4                   # => ((9/4)+2i)
Complex.rect(20, 9) / 9.8                 # => (2.0408163265306123+0.9183673469387754i)

Returns a Rational object whose value is exactly or approximately equivalent to that of self.real.

With no argument epsilon given, returns a Rational object whose value is exactly equal to that of self.real.rationalize:

Complex.rect(1, 0).rationalize              # => (1/1)
Complex.rect(1, Rational(0, 1)).rationalize # => (1/1)
Complex.rect(3.14159, 0).rationalize        # => (314159/100000)

With argument epsilon given, returns a Rational object whose value is exactly or approximately equal to that of self.real to the given precision:

Complex.rect(3.14159, 0).rationalize(0.1)          # => (16/5)
Complex.rect(3.14159, 0).rationalize(0.01)         # => (22/7)
Complex.rect(3.14159, 0).rationalize(0.001)        # => (201/64)
Complex.rect(3.14159, 0).rationalize(0.0001)       # => (333/106)
Complex.rect(3.14159, 0).rationalize(0.00001)      # => (355/113)
Complex.rect(3.14159, 0).rationalize(0.000001)     # => (7433/2366)
Complex.rect(3.14159, 0).rationalize(0.0000001)    # => (9208/2931)
Complex.rect(3.14159, 0).rationalize(0.00000001)   # => (47460/15107)
Complex.rect(3.14159, 0).rationalize(0.000000001)  # => (76149/24239)
Complex.rect(3.14159, 0).rationalize(0.0000000001) # => (314159/100000)
Complex.rect(3.14159, 0).rationalize(0.0)          # => (3537115888337719/1125899906842624)

Related: Complex#to_r.

Returns the real value for self:

Complex.rect(7).real     # => 7
Complex.rect(9, -4).real # => 9

If self was created with polar coordinates, the returned value is computed, and may be inexact:

Complex.polar(1, Math::PI/4).real # => 0.7071067811865476 # Square root of 2.

Returns false; for compatibility with Numeric#real?.

Returns the array [self.real, self.imag]:

Complex.rect(1, 2).rect # => [1, 2]

See Rectangular Coordinates.

If self was created with polar coordinates, the returned value is computed, and may be inexact:

Complex.polar(1.0, 1.0).rect # => [0.5403023058681398, 0.8414709848078965]

Complex#rectangular is an alias for Complex#rect.

Returns self.

Returns the value of self.real as a Float, if possible:

Complex.rect(1, 0).to_f              # => 1.0
Complex.rect(1, Rational(0, 1)).to_f # => 1.0

Raises RangeError if self.imag is not exactly zero (either Integer(0) or Rational(0, n)).

Returns the value of self.real as an Integer, if possible:

Complex.rect(1, 0).to_i              # => 1
Complex.rect(1, Rational(0, 1)).to_i # => 1

Raises RangeError if self.imag is not exactly zero (either Integer(0) or Rational(0, n)).

Returns a JSON string representing self:

require 'json/add/complex'
puts Complex(2).to_json
puts Complex(2.0, 4).to_json

Output:

{"json_class":"Complex","r":2,"i":0}
{"json_class":"Complex","r":2.0,"i":4}

Returns the value of self.real as a Rational, if possible:

Complex.rect(1, 0).to_r              # => (1/1)
Complex.rect(1, Rational(0, 1)).to_r # => (1/1)
Complex.rect(1, 0.0).to_r            # => (1/1)

Raises RangeError if self.imag is not exactly zero (either Integer(0) or Rational(0, n)) and self.imag.to_r is not exactly zero.

Related: Complex#rationalize.

Returns a string representation of self:

Complex.rect(2).to_s                      # => "2+0i"
Complex.rect(-8, 6).to_s                  # => "-8+6i"
Complex.rect(0, Rational(1, 2)).to_s      # => "0+1/2i"
Complex.rect(0, Float::INFINITY).to_s     # => "0+Infinity*i"
Complex.rect(Float::NAN, Float::NAN).to_s # => "NaN+NaN*i"