Class: Histogram

Inherits:
Object
  • Object
show all
Defined in:
lib/histogram.rb,
lib/histogram/version.rb

Defined Under Namespace

Classes: Error

Constant Summary collapse

VERSION = 
"0.1.1"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(values) ⇒ Histogram

Returns a new instance of Histogram.



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# File 'lib/histogram.rb', line 13

def initialize(values)
  @values = values
  @bin_count = BinCounter.evaluate(values)
  @bin_packer = BinPacker.new(@bin_count, values.min, values.max)
end

Instance Attribute Details

#bin_count ⇒ Object (readonly)

Returns the value of attribute bin_count.



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# File 'lib/histogram.rb', line 11

def bin_count
  @bin_count
end

Instance Method Details

#bin_width ⇒ Object 



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# File 'lib/histogram.rb', line 19

def bin_width
  @bin_packer.bin_width
end

#bins ⇒ Object 



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# File 'lib/histogram.rb', line 23

def bins
  @bins ||= @bin_packer.bins(values)
end

#render(title: nil, precision: 2, border: Terminal::Table::UnicodeBorder.new) ⇒ Object 



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# File 'lib/histogram.rb', line 27

def render(title: nil, precision: 2, border: Terminal::Table::UnicodeBorder.new)
  largest_bin = bins.max_by(&:count).count
  max_marker_count = [largest_bin, 12].min
  marker_width = largest_bin / max_marker_count

  rows = max_marker_count.times.map do |y|
    bins.size.times.map do |x|
      value = if (bins[x].count / marker_width.to_f).ceil > y
        "x"
      else
        ""
      end
      { value: value, alignment: :center }
    end
  end.reverse
  rows << bins.map { |bin| "(#{bin.count})" }

  border.top = false
  border.left = false
  border.right = false
  border.data[:y] = " "
  border.data[:n] = border.data[:nx]
  border.data[:ai] = border.data[:ax]
  border.data[:s] = border.data[:sx]

  headings = bins.map do |bin|
    min, max = bin.range.minmax
    if min == max
      min.to_s
    else
      "#{min.round(precision)}-#{max.round(precision)}"
    end
  end
  options = {
    headings: headings,
    rows: rows,
    style: {
      border: border,
    },
  }
  options[:title] = title if title

  output = Terminal::Table.new(**options).to_s

  lines = output.lines
  lines.delete_at(1) # delete header seperator
  header = if title
    lines.delete_at(1)
  else
    lines.shift
  end
  totals = lines.delete_at(-2)
  lines.last << "\n"
  lines << header
  lines << totals.chomp
  lines.join
end