Class: Treat::Learning::Export

Inherits:
Object
  • Object
show all
Defined in:
lib/treat/learning/export.rb

Overview

Represents a feature to be used in a classification task.

Direct Known Subclasses

Feature, Tag

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, default = nil, proc_string = nil) ⇒ Export

Initialize a feature for a classification problem.



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# File 'lib/treat/learning/export.rb', line 20

def initialize(name, default = nil, proc_string = nil)
  unless name.is_a?(Symbol)
    raise Treat::Exception,
    "The first argument to initialize should "+
    "be a symbol representing the name of the export."
  end
  if proc_string && !proc_string.is_a?(String)
    raise Treat::Exception,
    "The third argument to initialize, " +
    "if supplied, should be a string that " +
    "can be evaluated to yield a Proc."
  end
  @name, @default, @proc_string =
  name, default, proc_string
  begin
    @proc = proc_string ? 
    eval(proc_string) : nil
  rescue Exception => e
    raise Treat::Exception,
    "The third argument to initialize " +
    "did not evaluate without errors " +
    "(#{e.message})."
  end
  if @proc && !@proc.is_a?(Proc)
    raise Treat::Exception,
    "The third argument did not evaluate to a Proc."
  end
end

Instance Attribute Details

#default ⇒ Object (readonly)

The feature’s default value, if nil.



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# File 'lib/treat/learning/export.rb', line 12

def default
  @default
end

#name ⇒ Object (readonly)

The name of the feature. If no proc is supplied, this assumes that the target of your classification problem responds to the method corresponding to this name.



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# File 'lib/treat/learning/export.rb', line 10

def name
  @name
end

#proc ⇒ Object

A proc that can be used to perform calculations before storing a feature.



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# File 'lib/treat/learning/export.rb', line 15

def proc
  @proc
end

#proc_string ⇒ Object

The proc as a string value.



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# File 'lib/treat/learning/export.rb', line 17

def proc_string
  @proc_string
end

Instance Method Details

#==(feature) ⇒ Object

Custom comparison operator for features.



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# File 'lib/treat/learning/export.rb', line 50

def ==(feature)
  @name == feature.name &&
  @default == feature.default &&
  @proc_string == feature.proc_string
end