Mr. Park's original piece on slopegraphs: <a href="http://charliepark.org/slopegraphs/" rel="nofollow">http://charliepark.org/slopegraphs/</a><p>Previous Hacker News discussion of Mr. Park's original piece: <a href="http://news.ycombinator.com/item?id=2753343" rel="nofollow">http://news.ycombinator.com/item?id=2753343</a>