GoogleVisualr Gem - DataTabel with Roles Example

controller.rb

# http://code.google.com/apis/chart/interactive/docs/roles.html
def roles

  data_table = GoogleVisualr::DataTable.new
  data_table.new_column('string', 'Month')
  data_table.new_column('number', 'Sales')
  # Columns with role definition
  data_table.new_column('number'  , nil, nil, 'interval')
  data_table.new_column('number'  , nil, nil, 'interval')
  data_table.new_column('string'  , nil, nil, 'annotation')
  data_table.new_column('string'  , nil, nil, 'annotationText')
  data_table.new_column('boolean' , nil, nil, 'certainty')

  data_table.add_rows([
    ['April', 1000, 900 , 1100, 'A', 'Stolen data'  , true],
    ['May'  , 1170, 1000, 1200, 'B', 'Coffee spill' , true],
    ['June' , 660 , 550 , 800 , 'C', 'Wampus attack', true],
    ['July' , 1030, nil , nil , nil, nil            , false]
  ])

  opts   = { :width => 600, :height => 400, :title => 'Sales', :legend => 'none' }
  @chart = GoogleVisualr::Interactive::LineChart.new(data_table, opts)

end

view.html.erb

<div id='chart'></div>
<%= render_chart @chart, 'chart' %>

Hi Winston,

First of all, I want to thanks fr making such a nice tool for graphical representation of data. I used this gem in my application and i am stuck with one problem , Actually i want to block the Line chart for negative value of vAxis.

I have set minvalue for vAxis ({ :title=>"Instance",:minValue => 0 }) it works fine of value > 0 but whenever the value of vAxis become zero vAxis range start from -1 ,-0.5, 0 upto 1 which creates a problem for me. I want start vAxis from default value = 0. Please help me for if you have any idea.

Thanks,
Vijay Prasad