Gist to accompany my "How to make Tufte's discrete sparklines using d3.js" at http://dataviztalk.blogspot.com

blog_sparkline.js

var boston_record = [
    ['home', 'win'],
    ...
    ['away', 'loss'],
];

d3.select('#second-wrapper-main')
  .selectAll('div')
    .data(boston_record)
  .enter().append('div')
    .attr('class', 'drawn-line')
    .attr('data-binary-var', function (d) {
        if (d[1] === 'win') {
            return 1;
        }
        else {
            return 0;
        }
    })
    .style('left', function(d, i) { return i * 4 + 'px';});