Contours of San Francisco overlayed over OpenStreeMap vector tiles using code from mbostock's vector tiles with multiple layers example. View the hi-res file
See gist for code used to generate contours.
xxxxxxxxxx<meta charset="utf-8"><img src="https://gist.github.com/karmadude/5820393/raw/08438eb37a3a4b72ce3c6533f0f4e19751ded723/sfcontour.png" width="960" height="968"><script src="https://d3js.org/d3.v3.js"></script><script> d3.select(self.frameElement.parentElement) .style('background', '#6832b3') .style('background', '-moz-radial-gradient(center, ellipse cover, #6832b3 0%, #361370 100%)') .style('background', '-webkit-gradient(radial, center center, 0px, center center, 100%, color-stop(0%,#6832b3), color-stop(100%,#361370))') .style('background', '-webkit-radial-gradient(center, ellipse cover, #6832b3 0%,#361370 100%)'); d3.select(self.frameElement.parentElement).select("h1") .style('color', "#2B174B"); d3.select(self.frameElement) .style("height", "900px") .style("border", "none");</script> Modified http://d3js.org/d3.v3.js to a secure url
https://d3js.org/d3.v3.js