NumRu (NumPy in Ruby)

NumRu is adoption of NumPy in Ruby. The aim is not just to port NumPy to Ruby but to adopt it to Ruby syntax and ease.

Installation

1. You need Python 2 for this to work. It uses rubypython which currently only works for Python 2 but work is underway to make it work for Python 3.

2. Install numpy package for Python.

3. Add this line to your application's Gemfile:

gem 'numru'

And then execute:

$ bundle

Or install it yourself as:

$ gem install numru

Usage

1. Whatever works in NumPy works here. If there's something that doesn't work let me know in the issues.

require 'numru'
nr = NumRu

> x = nr.array 0..10
=> array([ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10])

> x = nr.arange(27).reshape 3, 3, 3
=> array([[[ 0,  1,  2],
        [ 3,  4,  5],
        [ 6,  7,  8]],

       [[ 9, 10, 11],
        [12, 13, 14],
        [15, 16, 17]],

       [[18, 19, 20],
        [21, 22, 23],
        [24, 25, 26]]])

2. Keyword arguments are not supported. For that use hash instead.

> x = nr.array [1, 2, 3], dtype: :complex
=> array([1.+0.j, 2.+0.j, 3.+0.j])

> x = nr.array [1, 2, 3], dtype: nr.int32
=> array([1, 2, 3], dtype=int32)

3. Indexing is similar to numpy except it use Ruby Range instead of Python Slice

> x = nr.array(20.times.map { |i| i**2 }).reshape 4, 5
=> array([[  0,   1,   4,   9,  16],
       [ 25,  36,  49,  64,  81],
       [100, 121, 144, 169, 196],
       [225, 256, 289, 324, 361]])
> x[0]
=> array([[ 0,  1,  4,  9, 16]])
> x[[0, 1]]
=> array([[ 0,  1,  4,  9, 16],
       [25, 36, 49, 64, 81]])
> x[0..1]
=> array([[ 0,  1,  4,  9, 16],
       [25, 36, 49, 64, 81]])
> x[0..-1, -1]
=> array([ 16,  81, 196, 361])
> x[0..-1, -2..-1]
=> array([[  9,  16],
       [ 64,  81],
       [169, 196],
       [324, 361]])

4. Slicing is supported too but it has to be wrapped inside quotes

> x = nr.arange(25).reshape(5, 5).T
=> array([[ 0,  5, 10, 15, 20],
       [ 1,  6, 11, 16, 21],
       [ 2,  7, 12, 17, 22],
       [ 3,  8, 13, 18, 23],
       [ 4,  9, 14, 19, 24]])
> x['::', '::-1']
=> array([[20, 15, 10,  5,  0],
       [21, 16, 11,  6,  1],
       [22, 17, 12,  7,  2],
       [23, 18, 13,  8,  3],
       [24, 19, 14,  9,  4]])
> x[':3', ':3']
=> array([[ 0,  5, 10],
       [ 1,  6, 11],
       [ 2,  7, 12]])

5. Operators work the way you expect

> x = nr.array 1..5
=> array([1, 2, 3, 4, 5])
> x > 3
=> array([False, False, False,  True,  True])
> x == 3
=> array([False, False,  True, False, False])
> x * 2
=> array([ 2,  4,  6,  8, 10])
> x * x
=> array([ 1,  4,  9, 16, 25])
> x % 3
=> array([1, 2, 0, 1, 2])

In development

The motive is not just to build a wrapper for NumPy but to adapt it to Ruby.

Rough plan

1. Provide all numpy functionality
2. Provide map, each, etc.
3. TODO: Think and discuss how to rubify the API

Contributing

• To report bugs please create an issue here
• If you have fixed a bug, then please create a PR here. While creating a PR please follow contributing guidelines

Note - This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Numru project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.