Class: Daru::MultiIndex

Inherits:
Index show all
Defined in:
lib/daru/index/multi_index.rb

Overview

rubocop:disable Metrics/ClassLength

Instance Attribute Summary collapse

Attributes inherited from Index

#relation_hash

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Index

__new__, #_dump, _load, coerce, inherited, #is_values, new, #slice, #sort, #subset_slice

Constructor Details

#initialize(opts = {}) ⇒ MultiIndex

names and levels should be of same size. If size of Array name is less or greater than size of array levels then it raises SizeError. If user don’t want to put name for particular level then user must put empty string in that index of Array name. For example there is multi_index of 3 levels and user don’t want to name level 0, then do multi_index.name = [”, ‘level1_name1’, ‘level2_name’]

Examples:


# set the name during initialization

mi = Daru::MultiIndex.new(
    levels: [[:a,:b,:c], [:one, :two]],
    labels: [[0,0,1,1,2,2], [0,1,0,1,0,1]], name: ['s1', 's2'])

# =>
# <Daru::MultiIndex(6x2)>
#   s1  s2
#    a one
#      two
#    b one
#      two
#    c one
#      two

# set new name

mi.name = ['k1', 'k2']
=> ["k1", "k2"]

mi
=>
#   #<Daru::MultiIndex(6x2)>
#   k1  k2
#    a one
#      two
#    b one
#      two
#    c one
#      two

# access the name

mi.name
=> ["k1", "k2"]

# If you don't want to name level 0

mi.name = ['', 'k2']
=> ["", "k2"]

mi
=>
#<Daru::MultiIndex(6x2)>
#       k2
#    a one
#      two
#    b one
#      two
#    c one
#      two

Raises:

  • (ArgumentError) 


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# File 'lib/daru/index/multi_index.rb', line 80

def initialize opts={}
  labels = opts[:labels]
  levels = opts[:levels]

  raise ArgumentError, 'Must specify both labels and levels' unless labels && levels
  raise ArgumentError, 'Labels and levels should be same size' if labels.size != levels.size
  raise ArgumentError, 'Incorrect labels and levels' if incorrect_fields?(labels, levels)

  @labels = labels
  @levels = levels.map { |e| e.map.with_index.to_h }
  self.name = opts[:name] unless opts[:name].nil?
end

Instance Attribute Details

#labels ⇒ Object (readonly)

Returns the value of attribute labels.



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# File 'lib/daru/index/multi_index.rb', line 11

def labels
  @labels
end

#name ⇒ Object

Returns the value of attribute name.



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# File 'lib/daru/index/multi_index.rb', line 12

def name
  @name
end

Class Method Details

.from_arrays(arrays) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 106

def self.from_arrays arrays
  levels = arrays.map { |e| e.uniq.sort_by(&:to_s) }

  labels = arrays.each_with_index.map do |arry, level_index|
    level = levels[level_index]
    arry.map { |lvl| level.index(lvl) }
  end

  MultiIndex.new labels: labels, levels: levels
end

.from_tuples(tuples) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 117

def self.from_tuples tuples
  from_arrays tuples.transpose
end

.try_from_tuples(tuples) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 121

def self.try_from_tuples tuples
  if tuples.respond_to?(:first) && tuples.first.is_a?(Array)
    from_tuples(tuples)
  else
    nil
  end
end

Instance Method Details

#&(other) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 300

def & other
  MultiIndex.from_tuples(to_a & other.to_a)
end

#==(other) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 323

def == other
  self.class == other.class  &&
    labels   == other.labels &&
    levels   == other.levels
end

#[](*key) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 129

def [] *key
  key.flatten!
  case
  when key[0].is_a?(Range)
    retrieve_from_range(key[0])
  when key[0].is_a?(Integer) && key.size == 1
    try_retrieve_from_integer(key[0])
  else
    begin
      retrieve_from_tuples key
    rescue NoMethodError
      raise IndexError, "Specified index #{key.inspect} do not exist"
    end
  end
end

#add(*indexes) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 199

def add *indexes
  Daru::MultiIndex.from_tuples(to_a + [indexes])
end

#at(*positions) ⇒ object

Takes positional values and returns subset of the self

capturing the indexes at mentioned positions

Examples:

idx = Daru::MultiIndex.from_tuples [[:a, :one], [:a, :two], [:b, :one], [:b, :two]]
idx.at 0, 1
# => #<Daru::MultiIndex(2x2)>
#   a one
#     two

Parameters:

  • positions (Array<Integer>) —

    positional values

Returns:

  • (object) —

    index object



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# File 'lib/daru/index/multi_index.rb', line 189

def at *positions
  positions = preprocess_positions(*positions)
  validate_positions(*positions)
  if positions.is_a? Integer
    key(positions)
  else
    Daru::MultiIndex.from_tuples positions.map(&method(:key))
  end
end

#coerce_index ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 251

def coerce_index
  if @levels.size == 1
    elements = to_a.flatten

    if elements.uniq.length == elements.length
      Daru::Index.new(elements)
    else
      Daru::CategoricalIndex.new(elements)
    end
  else
    self
  end
end

#conform(input_indexes) ⇒ Object

Provide a MultiIndex for sub vector produced

Parameters:

  • input_indexes (Array) —

    the input by user to index the vector

Returns:

  • (Object) —

    the MultiIndex object for sub vector produced



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# File 'lib/daru/index/multi_index.rb', line 351

def conform input_indexes
  return self if input_indexes[0].is_a? Range
  drop_left_level input_indexes.size
end

#drop_left_level(by = 1) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 292

def drop_left_level by=1
  MultiIndex.from_arrays to_a.transpose[by..-1]
end

#dup ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 288

def dup
  MultiIndex.new levels: levels.dup, labels: labels.dup, name: (@name.nil? ? nil : @name.dup)
end

#each(&block) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 3

def each(&block)
  to_a.each(&block)
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/daru/index/multi_index.rb', line 304

def empty?
  @labels.flatten.empty? && @levels.all?(&:empty?)
end

#include?(tuple) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/daru/index/multi_index.rb', line 308

def include? tuple
  return false unless tuple.is_a? Enumerable
  @labels[0...tuple.flatten.size]
    .transpose
    .include?(tuple.flatten.each_with_index.map { |e, i| @levels[i][e] })
end

#inspect(threshold = 20) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 337

def inspect threshold=20
  "#<Daru::MultiIndex(#{size}x#{width})>\n" +
    Formatters::Table.format([], headers: @name, row_headers: sparse_tuples, threshold: threshold)
end

#key(index) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/daru/index/multi_index.rb', line 280

def key index
  raise ArgumentError, "Key #{index} is too large" if index >= @labels[0].size

  @labels
    .each_with_index
    .map { |label, i| @levels[i].keys[label[index]] }
end

#levels ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 14

def levels
  @levels.map(&:keys)
end

#map(&block) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 7

def map(&block)
  to_a.map(&block)
end

#pos(*indexes) ⇒ Object

Note:

If the arugent is both a valid index and a valid position, it will treated as valid index

Returns positions given indexes or positions

Examples:

idx = Daru::MultiIndex.from_tuples [[:a, :one], [:a, :two], [:b, :one], [:b, :two]]
idx.pos :a
# => [0, 1]

Parameters:

  • indexes (Array<object>) —

    indexes or positions



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# File 'lib/daru/index/multi_index.rb', line 161

def pos *indexes
  if indexes.first.is_a? Integer
    return indexes.first if indexes.size == 1
    return indexes
  end
  res = self[indexes]
  return res if res.is_a? Integer
  res.map { |i| self[i] }
end

#remove_layer(layer_index) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 243

def remove_layer layer_index
  @levels.delete_at(layer_index)
  @labels.delete_at(layer_index)
  @name.delete_at(layer_index) unless @name.nil?

  coerce_index
end

#reorder(new_order) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 203

def reorder(new_order)
  from = to_a
  MultiIndex.from_tuples(new_order.map { |i| from[i] })
end

#size ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 315

def size
  @labels[0].size
end

#sparse_tuples ⇒ Object

Return tuples with nils in place of repeating values, like this:

:a , :bar, :one
nil, nil , :two
nil, :foo, :one


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# File 'lib/daru/index/multi_index.rb', line 362

def sparse_tuples
  tuples = to_a
  [tuples.first] + each_cons(2).map { |prev, cur|
    left = cur.zip(prev).drop_while { |c, p| c == p }
    [nil] * (cur.size - left.size) + left.map(&:first)
  }
end

#subset(*indexes) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 171

def subset *indexes
  if indexes.first.is_a? Integer
    MultiIndex.from_tuples(indexes.map { |index| key(index) })
  else
    self[indexes].conform indexes
  end
end

#to_a ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 329

def to_a
  (0...size).map { |e| key(e) }
end

#to_df ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 370

def to_df
  Daru::DataFrame.new(@name.zip(to_a.transpose).to_h)
end

#to_html ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 342

def to_html
  path = File.expand_path('../../iruby/templates/multi_index.html.erb', __FILE__)
  ERB.new(File.read(path).strip).result(binding)
end

#try_retrieve_from_integer(int) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 208

def try_retrieve_from_integer int
  @levels[0].key?(int) ? retrieve_from_tuples([int]) : int
end

#valid?(*indexes) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/daru/index/multi_index.rb', line 145

def valid? *indexes
  # FIXME: This is perhaps not a good method
  pos(*indexes)
  return true
rescue IndexError
  return false
end

#values ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 333

def values
  Array.new(size) { |i| i }
end

#width ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 319

def width
  @levels.size
end

#|(other) ⇒ Object 



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# File 'lib/daru/index/multi_index.rb', line 296

def | other
  MultiIndex.from_tuples(to_a | other.to_a)
end