Class: Arrow::Group

Inherits:
Object
  • Object
show all
Defined in:
lib/arrow/group.rb

Instance Method Summary collapse

Constructor Details

#initialize(table, keys) ⇒ Group

Returns a new instance of Group.



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# File 'lib/arrow/group.rb', line 20

def initialize(table, keys)
  @table = table
  @keys = keys
end

Instance Method Details

#aggregate(aggregation, *more_aggregations) ⇒ Object 



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# File 'lib/arrow/group.rb', line 57

def aggregate(aggregation, *more_aggregations)
  aggregations = [aggregation] + more_aggregations
  normalized_aggregations = normalize_aggregations(aggregations)
  plan = ExecutePlan.new
  source_node = plan.build_source_node(@table)
  aggregate_node =
    plan.build_aggregate_node(source_node,
                              {
                                aggregations: normalized_aggregations,
                                keys: @keys
                              })
  sink_node_options = SinkNodeOptions.new
  plan.build_sink_node(aggregate_node, sink_node_options)
  plan.validate
  plan.start
  plan.wait
  reader = sink_node_options.get_reader(aggregate_node.output_schema)
  reader.read_all
end

#count(*target_names) ⇒ Object 



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# File 'lib/arrow/group.rb', line 25

def count(*target_names)
  aggregate(*build_aggregations("hash_count", target_names))
end

#max(*target_names) ⇒ Object 



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# File 'lib/arrow/group.rb', line 45

def max(*target_names)
  aggregate(*build_aggregations("hash_max", target_names))
end

#mean(*target_names) ⇒ Object 



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# File 'lib/arrow/group.rb', line 37

def mean(*target_names)
  aggregate(*build_aggregations("hash_mean", target_names))
end

#min(*target_names) ⇒ Object 



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# File 'lib/arrow/group.rb', line 41

def min(*target_names)
  aggregate(*build_aggregations("hash_min", target_names))
end

#product(*target_names) ⇒ Object 



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# File 'lib/arrow/group.rb', line 33

def product(*target_names)
  aggregate(*build_aggregations("hash_product", target_names))
end

#stddev(*target_names) ⇒ Object 



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# File 'lib/arrow/group.rb', line 49

def stddev(*target_names)
  aggregate(*build_aggregations("hash_stddev", target_names))
end

#sum(*target_names) ⇒ Object 



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# File 'lib/arrow/group.rb', line 29

def sum(*target_names)
  aggregate(*build_aggregations("hash_sum", target_names))
end

#variance(*target_names) ⇒ Object 



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# File 'lib/arrow/group.rb', line 53

def variance(*target_names)
  aggregate(*build_aggregations("hash_variance", target_names))
end