 <p>How I centered a Topojson, where I needed to pull out the feature:</p> <pre><code> var projection = d3.geo.albersUsa(); var path = d3.geo.path() .projection(projection); var tracts = topojson.feature(mapdata, mapdata.objects.tx_counties); projection .scale(1) .translate([0, 0]); var b = path.bounds(tracts), s = .95 / Math.max((b[1][0] - b[0][0]) / width, (b[1][1] - b[0][1]) / height), t = [(width - s * (b[1][0] + b[0][0])) / 2, (height - s * (b[1][1] + b[0][1])) / 2]; projection .scale(s) .translate(t); svg.append("path") .datum(topojson.feature(mapdata, mapdata.objects.tx_counties)) .attr("d", path) </code></pre>