$el will do.
Don't need to use "window" here.
Show a 1 pixel bar for a zero value - could be the solution for #14.

Here's how you might show a different colour bar when it's zero.

    $("span").peity("bar", {
      colours: function(value) {
        return value == 0 ? "#ddd" : "#4d89f9"
      }
    })
Deal with multiple calls to `peity()`.

The first call applies default options, options from data-* attributes
and any included in the function call. Subsequent calls update the
chart's type and its options with any included in the function call.
Version 1.1.0.