require 'gnuplotrb'

include GnuplotRB

titles = %w{decade Austria Hungary Belgium}

data = [

['1891-1900', 234081, 181288, 18167],

['1901-1910', 668209, 808511, 41635],

['1911-1920', 453649, 442693, 33746],

['1921-1930', 32868, 30680, 15846],

['1931-1940', 3563, 7861, 4817],

['1941-1950', 24860, 3469, 12189],

['1951-1960', 67106, 36637, 18575],

['1961-1970', 20621, 5401, 9192],

]

x = data.map(&:first)

plots = (1..3).map do |col|

y = data.map { |row| row[col] }

Plot.new([[x, y], using: '2:xtic(1)', title: titles[col]])

end

mp = Multiplot.new(

*plots,

layout: [plots.size, 1],

style_data: 'histograms',

title: 'Histograms',

xtics: 'nomirror rotate by -45'

)

mp.to_png('./gnuplot_gem.png', size: [400,800])