Class: Symbolic::Variable

Inherits:
Object
  • Object
show all
Includes:
Symbolic
Defined in:
lib/symbolic/variable.rb

Overview

This class is used to create symbolic variables. Symbolic variables presented by name and value. Name is neccessary for printing meaningful symbolic expressions. Value is neccesary for calculation of symbolic expressions. If value isn't set for variable, but there is an associated proc, then value is taken from evaluating the proc.

Constant Summary

Constants included from Symbolic

OPERATIONS

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Symbolic

#*, #**, #+, #[email protected], #-, #[email protected], #/, #coerce, #factorial, #inspect, #operations, #taylor, #to_s

Constructor Details

#initialize(options = {}, &proc) ⇒ Variable

Create a new Symbolic::Variable, with optional name, value and proc


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# File 'lib/symbolic/variable.rb', line 15

def initialize(options={}, &proc)
  (@name, @value), @proc = options.values_at(:name, :value), proc
  @name = @name.to_s if @name
end

Instance Attribute Details

#nameObject

Returns the value of attribute name


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# File 'lib/symbolic/variable.rb', line 11

def name
  @name
end

#procObject

Returns the value of attribute proc


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# File 'lib/symbolic/variable.rb', line 11

def proc
  @proc
end

#valueObject


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# File 'lib/symbolic/variable.rb', line 20

def value
  @value || @proc && @proc.call.value
end

Instance Method Details

#diff(wrt) ⇒ Object


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# File 'lib/symbolic/variable.rb', line 39

def diff(wrt)
  return 1 if self == wrt
  0
end

#subs(to_replace, replacement = nil, expect_numeric = false) ⇒ Object


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# File 'lib/symbolic/variable.rb', line 28

def subs(to_replace, replacement=nil, expect_numeric = false)
  if replacement == nil and to_replace.is_a?(Hash)
	super(to_replace)
  else
	return replacement if self == to_replace
	#Consider the possibility that @value is not numeric?
	return self.value if expect_numeric
	self
  end
end

#variablesObject


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# File 'lib/symbolic/variable.rb', line 24

def variables
  [self]
end