Class: MathViz::Operation

Inherits:
Term show all
Defined in:
lib/mathviz.rb

Overview

n-ary operators

Direct Known Subclasses

Unary

Defined Under Namespace

Classes: Unary

Instance Attribute Summary

Attributes inherited from Term

#name

Instance Method Summary collapse

Methods inherited from Term

#anonymous?, binop, #data, #generated?, #label, list_terms, name_terms!, #style, #to_i, #to_s, unop

Methods included from Measured

#per, #unit, #with_units

Methods included from Units::Class

#included, #new_units

Constructor Details

#initialize(op, *operands) ⇒ Operation

Returns a new instance of Operation.



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# File 'lib/mathviz.rb', line 565

def initialize(op, *operands)
  super()
  @op = op
  @operands = operands.map{|x| MathViz.term(x)}
end

Instance Method Details

#collapse(parentop = nil) ⇒ Object

Combine anonymous nodes with the same operator to simply graph



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# File 'lib/mathviz.rb', line 634

def collapse(parentop = nil)
  @operands = @operands.flat_map {|x| x.collapse(@op)}
  if anonymous? && parentop == @op
    @operands
  else
    [self]
  end
end

#color ⇒ Object

Graphviz node color; differentiates basic mathematical operators (+, -, *, /)



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# File 'lib/mathviz.rb', line 587

def color
  case @op
  when :+; :green;
  when :-; :yellow;
  when :*; :blue;
  when :/; :cyan;
  else     :red;
  end
end

#constant? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mathviz.rb', line 625

def constant?
  @operands.all?(&:constant?)
end

#finite? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mathviz.rb', line 629

def finite?
  @operands.all?(&:finite?)
end

#link_from(g, other, style, label) ⇒ Object

Draws edges, and ensure the from nodes is drawn



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# File 'lib/mathviz.rb', line 598

def link_from(g, other, style, label)
  if label
    (g[other.to_s] >> g[node]) [:arrowhead => style, :headlabel => @op.to_s, :labeldistance => '2']
  else
    (g[other.to_s] >> g[node]) [:arrowhead => style]
  end
  other.to_dot(g) unless other.generated?
end

#long ⇒ Object

Debugging method; returns string of names and values



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# File 'lib/mathviz.rb', line 572

def long
  n = @name && (@name + " = ")
  "(#{n}#{@op} #{@operands.join(',')} = #{to_value})"
end

#shape ⇒ Object

Graphviz node shape; differentiates comparison operators



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# File 'lib/mathviz.rb', line 578

def shape
  if ([:>, :<, :>=, :<=, :&, :|, :==].include? @op)
    :ellipse
  else
    :box
  end
end

#to_dot(g) ⇒ Object

Extend Graphviz g with a representation of this object, and incoming connections



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# File 'lib/mathviz.rb', line 608

def to_dot(g)
  super
  link_from(g, @operands.first, :normal, false)
  @operands.slice(1..-1).each {|x| link_from(g, x, :onormal, true)}
end

#to_value ⇒ Object

Apply the operator to create the derived value.



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# File 'lib/mathviz.rb', line 615

def to_value
  return MathViz::Infinity unless finite?
  @operands.map(&:to_value).reduce(&@op)
end

#units ⇒ Object

Apply the operator to create the derived units.



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# File 'lib/mathviz.rb', line 621

def units
  @operands.map(&:units).reduce(&@op)
end