Sparker

Better Sparklines for Crystal

There are 2 parts to this.

• A library for adding sparkline capabilities to your command line apps
• A small executable that generates sparklines from your input

The Executable

Building

crystal build src/sparkline.cr

This will build a sparkline executable in the current directory. Just put it somewhere in your PATH and you're done.

Using

You can either pipe in a bunch of comma separate integers

echo "23, 64, 100" | sparkline # => ▁▅█

or you can pass them in as the first argument

sparkline "23, 64, 100" # => ▁▅█

If you pass them in as the first option you can also apply data fitting by passing "fit" as the second argument.

sparkline "23, 88, 100" fit # =>  ▄█

The Library

The Sparker clas takes an array of integers and converts it into a graph suitable for use in command line tools. It allows for custom characters for your graph. You could even get really funky and have HTML + CSS for each "character" and generate html graphs from command line data.

(NOTE: The HTML version of these examples have a weirdly uneven baseline in many browsers. Not to worry. They'll look great on your command line.)

For example:
This: [0, 30, 55, 80, 33, 150] becomes " ▁▂▄▁█"

Because tiny variations can get lost, especially with large numbers you can do data fitting to the smallest number. This is, of course, optional.

Maybe you'd like to use different characters for your graph? No worries. Sparker has you covered. You can even use multiple characters as a single bar tick. The more ticks you provide, the more precise the graph becomes.

Installation

Add this to your application's shard.yml:

dependencies:
  sparker:
    github: masukomi/sparker

Usage

require 'sparker'
include Sparkline

sparker = Sparker.new() 
sparker.generate([1, 5, 22, 13, 53])             #=> "  ▃▁█"
sparker.generate([0, 30, 55, 80, 33, 150])       # => " ▁▂▄▁█"

Want to use your own characters for the graph? Just initialize it with an array of them.

sparker = Sparker.new(["aa", "bb", "cc", "dd", "ee", "ff", "gg", "hh", "ii"]) 
sparker.generate([0, 30, 55, 80, 33, 150]) # => "aabbcceebbii"

Ok, that example wasn't the most useful, but you're a clever person. I'm sure you can think up something cool to do with that.

If you don't like the nothingness of the zero tick mark there's an alternate set of ticks built in with a tiny dot (U+0702) instead.

sparker = Sparker.new(Sparker::TICKS_2) # => "܂▁▂▃▄▅▆▇█"
sparker.generate [0, 30, 55, 80, 33, 150] # => "܂▁▂▄▁█"

As I mentioned above, you can turn on data fitting.When it's time to generate your graph, just pass in a second parameter of true to enable that feature.

# with data fitting
sparker.generate([88,100], true)    # =>" █"
# without data fitting
sparker.generate([88,100], false)   # => "▇█"
# with data fitting
sparker.generate([80,90,100], true) # =>" ▄█"
# without data fitting
sparker.generate([80,90,100], false) # => "▆▇█"

Contributing

1. Fork it ( https://github.com/masukomi/sparker/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
   • Please include unit tests
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request
6. Poke @masukomi on Twitter to make sure it gets seen promptly.

Contributors

Credits

Original Idea by Zack Holman. Ported to Python by Kenneth Reitz. Ported to Crystal (via Python) by Andrea Manzini and improved by masukomi.