Jupyter NB - Ruby kernel¶

I am developing IRuby a kernel in Ruby that adheres to the Jupyter/IPython messaging protocol. It integrates nicely with different Rubygems as will be shown later.

What does this give you?¶

This gives us a very fancy web notebook interface for Ruby. It's a very good tool for programming presentations. It's basically an in-browser REPL loop, with some extra goodies.

Usage¶

Install IRuby with:

gem install iruby

Start the IRuby notebook with:

iruby notebook

Example¶

$stdout and $stderr are redirected to the notebook

In [1]:

puts 'Hello, world!'

puts 'Hello, world!'

Hello, world!

In [2]:

$stderr.puts 'Error!'

$stderr.puts 'Error!'

Error!

The last computed result is returned.

In [3]:

Math.sqrt(2)

Math.sqrt(2)

Out[3]:

1.4142135623730951

This works even for images.

In [4]:

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

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

Out[4]:

In [5]:

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

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

Out[5]:

Display¶

IRuby provides a method to display objects IRuby.display and methods to create $\LaTeX$ and HTML representations.

In [6]:

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

IRuby.display 'Hello, world!', mime: 'text/html'

Hello, world!

In [7]:

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

IRuby.html ''

Out[7]:

$\LaTeX$ is rendered using MathJax.

In [8]:

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.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')

\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}

Out[8]:

$$F(k) = \int_{-\infty}^{\infty} f(x) e^{2\pi i k} dx$$

Arrays and Hashes can be printed as HTML tables.

In [9]:

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]])

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]])

1

2

3

a	b	c
1	2	3

11	12	13	14
21	22	23
not an Array
31	32	33	34

a	b	c
11	21	31
12	22	32
13	23	33
14		34

a	b	c	e
1	2	3
not an Array
2	3	4	5

a	b	c	d	0	1	2
1	2	3
2	3	4	5
				x	y
				a	b	c

Integration with Ruby gems¶

Pry¶

Pry is an enhanced Ruby REPL. It will be automatically used by IRuby if available. You can use the code browsing utilities for example.

In [10]:

ls Array

ls Array

Object.methods: yaml_tag
Array.methods: []  try_convert
Array#methods: 
  &            concat      hash                reject                slice     
  *            count       include?            reject!               slice!    
  +            cycle       index               repeated_combination  sort      
  -            delete      insert              repeated_permutation  sort!     
  <<           delete_at   inspect             replace               sort_by!  
  <=>          delete_if   join                reverse               take      
  ==           drop        keep_if             reverse!              take_while
  []           drop_while  last                reverse_each          to_a      
  []=          each        length              rindex                to_ary    
  any?         each_index  map                 rotate                to_h      
  assoc        empty?      map!                rotate!               to_s      
  at           eql?        pack                sample                transpose 
  bsearch      fetch       permutation         select                uniq      
  clear        fill        pop                 select!               uniq!     
  collect      find_index  pretty_print        shelljoin             unshift   
  collect!     first       pretty_print_cycle  shift                 values_at 
  combination  flatten     product             shuffle               zip       
  compact      flatten!    push                shuffle!              |         
  compact!     frozen?     rassoc              size                

Gnuplot¶

Gnuplot::Plot objects are automatically displayed inline as SVG.

In [11]:

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

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

Out[11]:

You can also create nice 3D plots

In [12]:

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

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

Out[12]:

Rubyvis¶

Rubyvis objects are automatically displayed inline as SVG.

In [13]:

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 '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

Out[13]:

Matrix & GSL¶

Matrix and GSL::Matrix objects are automatically displayed as $\LaTeX$.

In [14]:

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

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

Out[14]:

$$\left(\begin{array}{ccc} 1&2&3\\ 1&2&3\\ \end{array}\right)$$

Nyaplot¶

In [15]:

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

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