Chart.js configuration

gistfile1.coffee

chart_options: (data)->
  min = Math.min 0,data...
  max = Math.max data...
  num_of_y_ticks = 5
  scale_minmax_rounding_factor = if max > 10000 then 1000 else 500
  y_scale_rounding_factor = if max > 10000 then 5000 else 1000
  scale_max = scale_minmax_rounding_factor * Math.round(max/scale_minmax_rounding_factor)
  scale_min = scale_minmax_rounding_factor * Math.round(min/scale_minmax_rounding_factor)
  y_scale_step_size = (scale_max - scale_min) / (num_of_y_ticks)
  y_scale_step_rounded = y_scale_rounding_factor * Math.round(y_scale_step_size / y_scale_rounding_factor)
  num_of_y_ticks++ if y_scale_step_rounded < y_scale_step_size  # If the scale step size was decreased, we need to add a step
  
  showTooltips: true
  responsive: true
  scaleLabel: "£<%=value%>"
  scaleShowGridLines : false
  scaleOverride: true
  scaleSteps: num_of_y_ticks
  scaleStepWidth: y_scale_step_rounded
  scaleStartValue: scale_min                # Allow for negative values
  pointHitDetectionRadius : 3
  pointDot : false
  onAnimationComplete: _.debounce($.proxy(@_animated_chart, @), 50, true)
  onAnimationProgress: _.debounce($.proxy(@_animated_chart, @), 50, true)