Module: CollectdPlot::Plot

Defined in:
lib/collectd-plot/plot.rb

Class Method Summary collapse

Class Method Details

.example ⇒ Object 



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# File 'lib/collectd-plot/plot.rb', line 46

def self.example
  cmd = ''
  png_file = rand_filename
  Gnuplot::Plot.new(cmd) do |plot|
    plot.terminal "png"
    plot.output png_file

    plot.xrange "[0:10]"
    plot.title  "Sin Wave Example"
    plot.xlabel "x"
    plot.ylabel "y"
    plot.grid

    x = (0..50).collect { |v| v.to_f }
    y = x.collect { |v| v ** 2 }
    z = x.collect { |v| v * Math.sin(v) }

    plot.data << Gnuplot::DataSet.new( [x, y] ) do |ds|
      ds.with = "linespoints"
      ds.title = "quadratic"
      ds.linewidth = 4
    end 
    plot.data << Gnuplot::DataSet.new( [x, z] ) do |ds|
      ds.with = "linespoints"
      ds.title = "linear"
      ds.linewidth = 4
    end 
#      plot.data << Gnuplot::DataSet.new( "sin(x)" ) do |ds|
#        ds.with = "lines"
#      end
  end
  cmd << "\n\n\n"

  script = rand_filename
  File.open(script, 'w') { |f| f.write cmd }
  puts `gnuplot #{script}`
  puts `cat #{script} > gnuplot`
  f = File.open(png_file, "rb")
  png = f.read
  f.close
  File.delete png_file
  File.delete script
  png
end

.rand_filename ⇒ Object 



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# File 'lib/collectd-plot/plot.rb', line 6

def self.rand_filename()
  "/tmp/#{(0...10).map{65.+(rand(25)).chr}.join}.png"
end

.render(data, props) ⇒ Object 



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# File 'lib/collectd-plot/plot.rb', line 11

def self.render(data, props)
  cmd = ''
  png_file = rand_filename
  Gnuplot::Plot.new(cmd) do |plot|
    plot.terminal 'png'
    plot.output png_file

    #plot.xrange '[0:10]'
    plot.title "#{props.metric} for #{props.host}"
    plot.grid
    plot.xrange "[#{props.start}:#{props.finish}]"
    x = (props.start.to_i..props.finish.to_i).to_a

    data.each_pair do |h, d|
      plot.data << Gnuplot::DataSet.new( [x, d] ) do |ds|
        ds.linewidth = 4
        ds.title = props.host
      end
    end
  end
  cmd << "\n\n\n"

  script = rand_filename
  File.open(script, 'w') { |f| f.write cmd }
  puts `gnuplot #{script}`
  puts `cat #{script} > gnuplot`
  f = File.open(png_file, "rb")
  png = f.read
  f.close
  File.delete png_file
  File.delete script
  png
end