Class: HexWrench::Weka::Explorer::Header

Inherits:
Object
  • Object
show all
Defined in:
lib/hexwrench/weka/explorer.rb

Overview

represents an ARFF-like header

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(model, perspective_tree, resources_cnt = 0, name = "dummy") ⇒ Header

Returns a new instance of Header.



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# File 'lib/hexwrench/weka/explorer.rb', line 9

def initialize(model, perspective_tree, resources_cnt=0, name="dummy")
  @model = model
  if perspective_tree.is_a?(Array)
    @perspective = perspective_tree[0]
    @perspectives = perspective_tree[1]
  else
    @perspective = perspective_tree
    @perspectives = {}
  end
  @resources_cnt = resources_cnt
  @relation_name = name
end

Instance Attribute Details

#model ⇒ Object (readonly)

Returns the value of attribute model.



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# File 'lib/hexwrench/weka/explorer.rb', line 8

def model
  @model
end

#perspective ⇒ Object (readonly)

Returns the value of attribute perspective.



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# File 'lib/hexwrench/weka/explorer.rb', line 8

def perspective
  @perspective
end

#perspectives ⇒ Object (readonly)

Returns the value of attribute perspectives.



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# File 'lib/hexwrench/weka/explorer.rb', line 8

def perspectives
  @perspectives
end

#relation_name ⇒ Object (readonly)

Returns the value of attribute relation_name.



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# File 'lib/hexwrench/weka/explorer.rb', line 8

def relation_name
  @relation_name
end

#resources_cnt ⇒ Object (readonly)

Returns the value of attribute resources_cnt.



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# File 'lib/hexwrench/weka/explorer.rb', line 8

def resources_cnt
  @resources_cnt
end

Instance Method Details

#add_resource(resource) ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 150

def add_resource(resource)
  add_resource_to_instances(resource, instances)
end

#add_resource_to_instances(resource, instances) ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 146

def add_resource_to_instances(resource, instances)
  add_values_to_instances(values_for_resources(resource), instances)
end

#add_values_to_instances(values, instances) ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 142

def add_values_to_instances(values, instances)
  instances.add(Weka::Instance.new(1.0, values.to_java(Java::double)))
end

#attribute(name) ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 28

def attribute(name)
  pair = attributes_pairs.find{|n, attr| n == name}
  pair.last if pair
end

#attribute_for_feature(feat) ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 64

def attribute_for_feature(feat)
  name = File.join(relation_name, feat.sym.to_s)
  case feat
  when NumericFeature
    Weka::Attribute.new(name)
  when DateFeature
    Weka::Attribute.new(name, feat.weka_format)
  when NominalFeature
    Weka::Attribute.new(name, feat.labels_fv)
  when StringFeature
    construct = Weka::Attribute.java_class.constructor(java.lang.String, 
                                                       Weka::FastVector)
    construct.new_instance(name, nil).to_java
  when RelationFeature
    related_model = feat.related_model
    related_persp = perspectives[feat.sym] || :default 
    cnt = 0 #XXX could be taken more cleverly if support in Welo's relationship
    header = Header.new(related_model, related_persp, cnt, name)
    headers[feat.sym] = header
    construct = Weka::Attribute.java_class.constructor(java.lang.String, 
                                                       Weka::Instances)
    construct.new_instance(name, header.instances).to_java
  else
    raise ArgumentError, "don't know how to handler #{feat} to make an attribute"
  end
end

#attributes ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 33

def attributes
  attributes_pairs.map{|name, attr| attr}
end

#attributes_pairs ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 37

def attributes_pairs
  @attributes_pairs ||= create_attributes_pairs
end

#create_attributes_pairs ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 49

def create_attributes_pairs
  features.map do |feat|
    [feat.sym, attribute_for_feature(feat)]
  end
end

#create_fast_vector ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 91

def create_fast_vector
  fv = Weka::FastVector.new
  attributes.each do |attribute|
    fv.add_element(attribute)
  end
  fv
end

#create_instances ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 99

def create_instances
  Weka::Instances.new(relation_name, fast_vector, resources_cnt)
end

#fast_vector ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 41

def fast_vector
  @fast_vector ||= create_fast_vector
end

#features ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 22

def features
  model.perspective(perspective).fields.map do |sym|
    model.feature(sym)
  end
end

#header(name) ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 60

def header(name)
  headers[name]
end

#headers ⇒ Object

headers for related attributes



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# File 'lib/hexwrench/weka/explorer.rb', line 56

def headers
  @headers ||= {}
end

#instances ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 45

def instances
  @instances ||= create_instances
end

#new_data_instances ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 139

def new_data_instances
end

#values_for_resources(resource) ⇒ Object 



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# File 'lib/hexwrench/weka/explorer.rb', line 103

def values_for_resources(resource)
  features.map do |feat|
    rb_val = resource.send(feat.sym)
    attribute = attribute(feat.sym)
    val = case feat
          when DateFeature
            date_str = if rb_val.respond_to?(:strftime)
                         fmt = feat.format || DateFeature.default_format
                         rb_val.send(:strftime, fmt)
                       else
                         rb_val
                       end
            attribute.parseDate(date_str) 
          when NominalFeature
            attribute.indexOfValue(rb_val.to_s.to_java)
          when StringFeature
            attribute.addStringValue(rb_val.to_java)
          when RelationFeature
            header = header(feat.sym) 
            raise NotImplementedError, "no header built for #{feat} yet" unless header
            data_instances = Weka::Instances.new(attribute.relation, 0)
            if feat.relationship.many?
              rb_val.each do |rb_val_|
                header.add_resource_to_instances(rb_val_, data_instances)
              end
            else
              header.add_resource_to_instances(rb_val, data_instances)
            end
            attribute.addRelation(data_instances) 
          else
            rb_val
          end
    val
  end
end