Heatmap
=======

Heatmap provides a simple, single helper method that generates a cloud-style heatmap based on a provided histogram.

Installation
============

Install the plugin as usual:

  script/plugin install git@github.com:Bantik/heatmap.git
  
Then add this line to your application controller:

  helper_method :heatmap

That's it!

Example
=======

To generate a heatmap, simply call the method from the view, passing in a preprepared histogram. The size and color of each key is calculated based on the associated value from the histogram.

In the controller:

  def index
    @histogram = {
      'Foo' => 13,
      'Bar' => 15,
      'Trouble' => 5,
      'Braids' => 1,
      'Something' => 9,
      'Else' => 13,
      'Many' => 20,
      'Zombies' => 7,
      'nothing' => 0
    }
  end

In your view:

  <%= heatmap(@histogram) -%>

You'll probably want to style the heatmap. There are two classes that you need to set styles for: heatmap, which is the enclosing div, and heatmap_element, which is applied to each key in the heatmap.

Sample CSS to get you started:

    .heatmap {
      border-top: 1px solid #aaaaaa;
      border-bottom: 1px solid #aaaaaa;
      width: 300px;
      padding: 1em;
    }

    .heatmap_element {
      display: block;
      text-align: center;
      margin: .25em;
      padding-top: 0em;
      float: left;
    }

Copyright (c) 2010 Corey Ehmke, released under the MIT license