README.md in matrix-0.1.0 vs README.md in matrix-0.3.0
- old
+ new
@@ -1,31 +1,35 @@
-# Matrix
+# Matrix [](https://badge.fury.io/rb/matrix) [](https://stdgems.org/matrix/) [](https://travis-ci.com/ruby/matrix)
An implementation of `Matrix` and `Vector` classes.
-The `Matrix` class represents a mathematical matrix. It provides methods for creating matrices, operating on them arithmetically and algebraically, and determining their mathematical properties (trace, rank, inverse, determinant).
+The `Matrix` class represents a mathematical matrix. It provides methods for creating matrices, operating on them arithmetically and algebraically, and determining their mathematical properties (trace, rank, inverse, determinant, eigensystem, etc.).
The `Vector` class represents a mathematical vector, which is useful in its own right, and also constitutes a row or column of a `Matrix`.
## Installation
-Add this line to your application's Gemfile:
+The `matrix` library comes pre-installed with Ruby. Unless you need recent features, you can simply `require 'matrix'` directly, no need to install it.
+If you need features that are more recent than the version of Ruby you want to support (check the [CHANGELOG](CHANGELOG.md)), you must use the gem. To do this, add this line to your application's Gemfile or gem's gemspec:
+
```ruby
gem 'matrix'
```
And then execute:
$ bundle
-Or install it yourself as:
+To make sure the gem takes over the builtin library, be to call `bundle exec ...` (or to call `gem 'matrix' explicitly).
- $ gem install matrix
-
## Usage
-TODO: Write usage instructions here
+```ruby
+require 'matrix'
+m = Matrix[[1, 2], [3, 4]]
+m.determinant # => -2
+```
## Development
After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake test` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.