examples/plot_histogram/plot.rb
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)
datasets = (1..3).map do |col|
y = data.map { |row| row[col] }
Dataset.new([x, y], using: '2:xtic(1)', title: titles[col], file: true)
end
plot = Plot.new(*datasets, title: 'Histogram example', style: 'data histograms', xtics: 'nomirror rotate by -45')
plot.to_png('./gnuplot_gem.png', size: [600, 600])