Class: Vangrail::Judgement

Inherits:
Struct
  • Object
show all
Defined in:
lib/vangrail/judgement.rb

Overview

What to do with a posterior, and what the numbers were.

A Result answers "did a rail stop this". A Judgement answers a different question: given everything that ran, how likely is it that this text is an attack, and is that likely enough to act on. The two are not interchangeable and the second is the one an operator can set a policy against.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#action ⇒ Object

Returns the value of attribute action

Returns:

  • (Object) —

    the current value of action



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# File 'lib/vangrail/judgement.rb', line 12

def action
  @action
end

#bits ⇒ Object

Returns the value of attribute bits

Returns:

  • (Object) —

    the current value of bits



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# File 'lib/vangrail/judgement.rb', line 12

def bits
  @bits
end

#certain ⇒ Object

Returns the value of attribute certain

Returns:

  • (Object) —

    the current value of certain



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# File 'lib/vangrail/judgement.rb', line 12

def certain
  @certain
end

#contributions ⇒ Object

Returns the value of attribute contributions

Returns:

  • (Object) —

    the current value of contributions



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# File 'lib/vangrail/judgement.rb', line 12

def contributions
  @contributions
end

#origin ⇒ Object

Returns the value of attribute origin

Returns:

  • (Object) —

    the current value of origin



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# File 'lib/vangrail/judgement.rb', line 12

def origin
  @origin
end

#posterior ⇒ Object

Returns the value of attribute posterior

Returns:

  • (Object) —

    the current value of posterior



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# File 'lib/vangrail/judgement.rb', line 12

def posterior
  @posterior
end

#prior ⇒ Object

Returns the value of attribute prior

Returns:

  • (Object) —

    the current value of prior



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# File 'lib/vangrail/judgement.rb', line 12

def prior
  @prior
end

#side ⇒ Object

Returns the value of attribute side

Returns:

  • (Object) —

    the current value of side



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# File 'lib/vangrail/judgement.rb', line 12

def side
  @side
end

#skipped ⇒ Object

Rails not run because the action was already settled: no remaining evidence could have changed it. Different in kind from a rail that could not run, which is why this is a separate field from certain?.



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# File 'lib/vangrail/judgement.rb', line 12

def skipped
  @skipped
end

Instance Method Details

#allow? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/vangrail/judgement.rb', line 22

def allow?
  action == :allow
end

#block? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/vangrail/judgement.rb', line 14

def block?
  action == :block
end

#certain? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/vangrail/judgement.rb', line 26

def certain?
  certain
end

#channel ⇒ Object 



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# File 'lib/vangrail/judgement.rb', line 49

def channel
  origin&.channel
end

#factor ⇒ Object

How far the evidence moved the odds, as a multiplier. Bits are the honest unit and this is the readable one.



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# File 'lib/vangrail/judgement.rb', line 38

def factor
  2**bits
end

#fired ⇒ Object

The rails that fired, most telling first, which is what a person reading a flagged page wants before anything else.



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# File 'lib/vangrail/judgement.rb', line 32

def fired
  contributions.select { |c| c[:fired] }.sort_by { |c| -c[:bits] }
end

#review? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/vangrail/judgement.rb', line 18

def review?
  action == :review
end

#silence ⇒ Object

The rails that said nothing, as one entry rather than a list of them.

Their bits are what pushes a clean page below its prior, so a payload carrying only the rails that fired shows a posterior under the prior with nothing to account for it: the numbers on the page do not add up to the decision the page is reporting. One entry keeps them adding up without listing thirty rails that had nothing to say.



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# File 'lib/vangrail/judgement.rb', line 60

def silence
  quiet = contributions.reject { |c| c[:fired] }
  return nil if quiet.empty?

  { 'rails' => quiet.size, 'bits' => quiet.sum { |c| c[:bits] }.round(2) }
end

#to_h ⇒ Object 



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# File 'lib/vangrail/judgement.rb', line 67

def to_h
  {
    'side' => side.to_s,
    'origin' => origin&.to_s,
    'channel' => channel&.to_s,
    'prior' => prior,
    'posterior' => posterior.round(6),
    'bits' => bits.round(2),
    'action' => action.to_s,
    'certain' => certain?,
    'fired' => fired.map { |c| { 'rail' => c[:rail], 'bits' => c[:bits].round(2) } },
    'silent' => silence,
    'skipped' => (skipped unless skipped.empty?),
  }.compact
end

#to_s ⇒ Object 



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# File 'lib/vangrail/judgement.rb', line 83

def to_s
  parts = [format('%<action>s p=%<posterior>.4f (prior %<prior>g, %<bits>+.1f bits)',
                  action: action, posterior: posterior, prior: prior, bits: bits)]
  parts << "fired: #{fired.map { |c| c[:rail] }.join(', ')}" unless fired.empty?
  parts << 'uncertain' unless certain?
  parts.join(' ')
end