Module: Batsd::Dash::GraphHelper

Defined in:
lib/batsd-dash/graph.rb

Instance Method Summary collapse

Instance Method Details

#transform_point_at!(index, values) ⇒ Object

Transform a point at a given index. Works against values array

Parameters:

  • index (Integer)
  • values (Array) —

    array of values



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# File 'lib/batsd-dash/graph.rb', line 49

def transform_point_at!(index, values)
  data_pt = values[index]

  # we've already transformed this index (must be zerofill)
  return data_pt unless Hash === data_pt

  pt_time = data_pt['timestamp'].to_i * 1000
  pt_value = data_pt['value'].to_f

  values[index] = [pt_time, pt_value]
end

#values_for_graph(values, opts = {}) ⇒ Array

This method works directly against values. It will tranform all datapoint to an array where the first element is a milisecond timestamp and the second is a float value data point.

Parameters:

  • values (Array) —

    array of datapoints

  • opts (Hash) (defaults to: {}) —

    optional options hash

Returns:

  • (Array) —

    modified values array



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# File 'lib/batsd-dash/graph.rb', line 12

def values_for_graph(values, opts = {})
  return values if values.empty?

  values.tap do |pts|
    step = opts[:interval] * 1000
    range = opts[:range]

    # transform the first point
    transform_point_at!(0, values)

    # start from the first timestamp
    time = values.first.first + step
    index = 0

    # loop through values to transform and zerofill
    while index < values.size - 1
      obj = transform_point_at!(index += 1, values)
      next unless opts[:zero_fill]

      if obj.first <= time
        time += step
        next
      end

      # need to insert zerofilled point (if zerofill is enabled)
      values.insert(index, [time, 0])
      time += step
    end
  end
end