Class: Geometry::Point

Inherits:
Vector
  • Object
show all
Defined in:
lib/geometry/point.rb

Overview

An object repesenting a Point in N-dimensional space

Supports all of the familiar Vector methods and adds convenience accessors for those variables you learned to hate in your high school geometry class (x, y, z).

Usage

Constructor

point = Geometry::Point[x,y]

Constant Summary

Constants inherited from Vector

Vector::X, Vector::Y, Vector::Z

Accessors collapse

Accessors collapse

Unary operators collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Vector

#cross

Instance Attribute Details

#x ⇒ Numeric (readonly)

Returns X-component.

Returns:

  • (Numeric) —

    X-component



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# File 'lib/geometry/point.rb', line 104

def x
  @x
end

#y ⇒ Numeric (readonly)

Returns Y-component.

Returns:

  • (Numeric) —

    Y-component



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# File 'lib/geometry/point.rb', line 110

def y
  @y
end

#z ⇒ Numeric (readonly)

Returns Z-component.

Returns:

  • (Numeric) —

    Z-component



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# File 'lib/geometry/point.rb', line 116

def z
  @z
end

Class Method Details

.[](x, y, z, ...) ⇒ Object .[](Array) ⇒ Object .[](Point) ⇒ Object .[](Vector) ⇒ Object

Allow vector-style initialization, but override to support copy-init from Vector or another Point



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# File 'lib/geometry/point.rb', line 31

def self.[](*array)
    return array[0] if array[0].is_a?(Point) or array[0].is_a?(PointZero)
    array = array[0] if array[0].is_a?(Array)
    array = array[0].to_a if array[0].is_a?(Vector)
    super *array
end

.zero(size = nil) ⇒ PointZero

Creates and returns a new Geometry::PointZero instance. Or, a Geometry::Point full of zeros if the size argument is given.

Parameters:

  • size (Number) (defaults to: nil) —

    the size of the new Geometry::Point full of zeros

Returns:



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# File 'lib/geometry/point.rb', line 41

def self.zero(size=nil)
    size ? Point[Array.new(size, 0)] : PointZero.new
end

Instance Method Details

#+(other) ⇒ Object 



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# File 'lib/geometry/point.rb', line 133

def +(other)
    case other
	when Numeric
	    Point[@elements.map {|e| e + other}]
	when PointZero, NilClass
	    self.dup
	else
	    raise OperationNotDefined, "#{other.class} must respond to :size and :[]" unless other.respond_to?(:size) && other.respond_to?(:[])
	    raise DimensionMismatch,  "Can't add #{other} to #{self}" if size != other.size
	    Point[Array.new(size) {|i| @elements[i] + other[i] }]
    end
end

#+@ ⇒ Object 



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# File 'lib/geometry/point.rb', line 124

def +@
    self
end

#-(other) ⇒ Object 



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# File 'lib/geometry/point.rb', line 146

def -(other)
    case other
	when Numeric
	    Point[@elements.map {|e| e - other}]
	when PointZero, NilClass
	    self.dup
	else
	    raise OperationNotDefined, "#{other.class} must respond to :size and :[]" unless other.respond_to?(:size) && other.respond_to?(:[])
	    raise DimensionMismatch, "Can't subtract #{other} from #{self}" if size != other.size
	    Point[Array.new(size) {|i| @elements[i] - other[i] }]
    end
end

#-@ ⇒ Object 



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# File 'lib/geometry/point.rb', line 128

def -@
    Point[@elements.map {|e| -e }]
end

#<=>(other) ⇒ Point

Combined comparison operator

Returns:

  • (Point) —

    The <=> operator is applied to the elements of the arguments pairwise and the results are returned in a Point



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# File 'lib/geometry/point.rb', line 74

def <=>(other)
    Point[self.to_a.zip(other.to_a).map {|a,b| a <=> b}.compact]
end

#==(other) ⇒ Object

Allow comparison with an Array, otherwise do the normal thing



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# File 'lib/geometry/point.rb', line 62

def ==(other)
    if other.is_a?(Array)
	@elements.eql? other
    elsif other.is_a?(PointZero)
	@elements.all? {|e| e.eql? 0 }
    else
	super other
    end
end

#[](i) ⇒ Numeric

Returns Element i (starting at 0).

Parameters:

Returns:

  • (Numeric) —

    Element i (starting at 0)



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# File 'lib/geometry/point.rb', line 98

def [](i)
    @elements[i]
end

#clone ⇒ Object

Return a copy of the Geometry::Point



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# File 'lib/geometry/point.rb', line 46

def clone
    Point[@elements.clone]
end

#coerce(other) ⇒ Object 



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# File 'lib/geometry/point.rb', line 78

def coerce(other)
    case other
	when Array then [Point[*other], self]
	when Numeric then [Point[Array.new(self.size, other)], self]
	when Vector then [Point[*other], self]
	else
	    raise TypeError, "#{self.class} can't be coerced into #{other.class}"
    end
end

#eql?(other) ⇒ Boolean

Allow comparison with an Array, otherwise do the normal thing

Returns:

  • (Boolean) 


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# File 'lib/geometry/point.rb', line 51

def eql?(other)
    if other.is_a?(Array)
	@elements.eql? other
    elsif other.is_a?(PointZero)
	@elements.all? {|e| e.eql? 0 }
    else
	super other
    end
end

#inspect ⇒ Object 



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# File 'lib/geometry/point.rb', line 88

def inspect
    'Point' + @elements.inspect
end

#to_s ⇒ Object 



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# File 'lib/geometry/point.rb', line 91

def to_s
    'Point' + @elements.to_s
end