Class: RubyPx::Dataset

Inherits:
Object
  • Object
show all
Defined in:
lib/ruby_px/dataset.rb,
lib/ruby_px/dataset/data.rb

Defined Under Namespace

Classes: Data

Constant Summary collapse

METADATA_RECORDS = 
%w[TITLE UNITS SOURCE CONTACT LAST-UPDATED CREATION-DATE].freeze
HEADING_RECORD = 
'HEADING'
STUB_RECORD = 
'STUB'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(resource_uri) ⇒ Dataset

Returns a new instance of Dataset.



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# File 'lib/ruby_px/dataset.rb', line 15

def initialize(resource_uri)
  @metadata = {}
  @headings = []
  @stubs = []
  @values = {}
  @data = Data.new

  parse_resource(resource_uri)
end

Instance Attribute Details

#headings ⇒ Object (readonly)

Returns the value of attribute headings.



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# File 'lib/ruby_px/dataset.rb', line 9

def headings
  @headings
end

#stubs ⇒ Object (readonly)

Returns the value of attribute stubs.



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# File 'lib/ruby_px/dataset.rb', line 9

def stubs
  @stubs
end

Instance Method Details

#contact ⇒ Object 



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# File 'lib/ruby_px/dataset.rb', line 37

def contact
  @metadata['CONTACT']
end

#creation_date ⇒ Object 



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# File 'lib/ruby_px/dataset.rb', line 45

def creation_date
  @metadata['CREATION-DATE']
end

#data(options) ⇒ Object 



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# File 'lib/ruby_px/dataset.rb', line 57

def data(options)
  # Validate parameters
  options.each do |k, v|
    unless dimension(k).include?(v)
      raise "Invalid value #{v} for dimension #{k}"
    end
  end

  # Return a single value
  # 2D array[ i*M + j]
  # 3D array[ i*(N*M) + j*M + k ]
  # 4D array[ i*(N*M*R) + j*M*R + k*R + l]
  if options.length == dimensions.length
    offset = 0

    # positions are i, j, k
    positions = (stubs + headings).map do |dimension_name|
      dimension(dimension_name).index(options[dimension_name])
    end

    # dimension_sizes are from all dimensions except the first one
    dimension_sizes = (stubs + headings)[1..-1].map do |dimension_name|
      dimension(dimension_name).length
    end

    positions.each_with_index do |p, i|
      d = dimension_sizes[i..-1].reduce(&:*)
      offset += (d ? p * d : p)
    end

    @data.at(offset)

  # Return an array of options
  elsif options.length == dimensions.length - 1
    result = []

    missing_dimension = (dimensions - options.keys).first
    dimension(missing_dimension).each do |dimension_value|
      result << data(options.merge(missing_dimension => dimension_value))
    end

    result
  else
    raise 'Not implented yet, sorry'
  end
end

#dimension(name) ⇒ Object 



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# File 'lib/ruby_px/dataset.rb', line 49

def dimension(name)
  @values[name] || raise("Missing dimension #{name}")
end

#dimensions ⇒ Object 



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# File 'lib/ruby_px/dataset.rb', line 53

def dimensions
  @values.keys
end

#inspect ⇒ Object 



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# File 'lib/ruby_px/dataset.rb', line 104

def inspect
  "#<#{self.class.name}:#{object_id}>"
end

#last_updated ⇒ Object 



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# File 'lib/ruby_px/dataset.rb', line 41

def last_updated
  @metadata['LAST-UPDATED']
end

#source ⇒ Object 



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# File 'lib/ruby_px/dataset.rb', line 33

def source
  @metadata['SOURCE']
end

#title ⇒ Object 



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# File 'lib/ruby_px/dataset.rb', line 25

def title
  @metadata['TITLE']
end

#units ⇒ Object 



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# File 'lib/ruby_px/dataset.rb', line 29

def units
  @metadata['UNITS']
end