puts 'Hello, world!'

$stderr.puts 'Error!'

Math.sqrt(2)

File.open('IRuby Examples/ruby.svg')

File.open('IRuby Examples/ruby.png')

IRuby.display '<b style="color:green">Hello, world!</b>', mime: 'text/html'

IRuby.html '<iframe src=http://en.mobile.wikipedia.org/?useformat=mobile width=700 height=350></iframe>'

IRuby.display IRuby.latex <<-'TEX'
\begin{eqnarray}
\nabla \times \vec{\mathbf{B}} -\, \frac1c\, \frac{\partial\vec{\mathbf{E}}}{\partial t} & = \frac{4\pi}{c}\vec{\mathbf{j}} \\
\nabla \cdot \vec{\mathbf{E}} & = 4 \pi \rho \\
\nabla \times \vec{\mathbf{E}}\, +\, \frac1c\, \frac{\partial\vec{\mathbf{B}}}{\partial t} & = \vec{\mathbf{0}} \\
\nabla \cdot \vec{\mathbf{B}} & = 0 
\end{eqnarray}
TEX

IRuby.math('F(k) = \int_{-\infty}^{\infty} f(x) e^{2\pi i k} dx')

IRuby.display IRuby.table([1,2,[],3])
IRuby.display IRuby.table({a:1,b:2,c:3})
IRuby.display IRuby.table([[11,12,13,14],[21,22,23],'not an Array',[31,32,33,34]])
IRuby.display IRuby.table({a:[11,12,13,14],b:[21,22,23],c:[31,32,33,34]})
IRuby.display IRuby.table([{a:1,b:2,c:3},'not an Array',{a:2,b:3,c:4,e:5}])
IRuby.display IRuby.table([{a:1,b:2,c:3},{a:2,b:3,c:4,d:5},{0=>:x,1=>:y},[:a,:b,:c]])

ls Array

require 'gnuplot'

Gnuplot::Plot.new do |plot|  
    plot.xrange '[-0.5:0.5]'
    plot.title  'Example plot'
    plot.ylabel 'x'
    plot.xlabel 'sin(1/x)'
    plot.samples 10000
    plot.data << Gnuplot::DataSet.new('sin(1/x)') do |ds|
        ds.with = 'lines'
        ds.linewidth = 2
    end
end

Gnuplot::SPlot.new do |plot|
    plot.title 'Spiral'
    plot.nokey
    plot.parametric
    plot.hidden3d
    plot.view '80,50'
    plot.isosamples '60,15'
    plot.xrange '[-8:8]'
    plot.yrange '[-8:8]'
    plot.zrange '[-8:8]'
    plot.urange '[-2*pi:2*pi]'
    plot.vrange '[-pi:pi]'
    plot.data << Gnuplot::DataSet.new('cos(u)*(cos(v)+3), sin(u)*(cos(v)+3), sin(v)+u') do |ds|
        ds.with = 'lines'
    end
end

require 'rubyvis'
    
Rubyvis::Panel.new do 
  width 150
  height 150
  bar do
    data [1, 1.2, 1.7, 1.5, 0.7, 0.3]
    width 20
    height {|d| d * 80}
    bottom(0)
    left {index * 25}
  end
end

require 'matrix'
Matrix[[1,2,3],[1,2,3]]

require 'nyaplot'

x = []; y = []; theta = 0.6; a=1
while theta < 14*Math::PI do
  x.push(a*Math::cos(theta)/theta)
  y.push(a*Math::sin(theta)/theta)
  theta += 0.1
end
plot1 = Nyaplot::Plot.new
plot1.add(:line, x, y)
plot1.show