     color_val = (iso3)->
         if data_by_iso[iso3] then colorize(data_by_iso[iso3]) else '#eeeeee'
 
+    # Zoom map on mouse click. If clicked on country and not zoomed, zoom in,
+    # else zoom out and center map.
     clicked = (d)->
         x = null
         y = null

        columns = d3.keys(data[0]).filter(
            (d)-> if d isnt '' and d isnt 'iso3' then d else null).sort()

    geomap.update = ()->
        update()


            .attr('transform', 'translate(' + width / 2 + ',' + height / 2 + ')scale(' + k + ')translate(' + -x + ',' + -y + ')')
            .style('stroke-width', 1 / k + 'px')

    # Calculate data mapping, draw and colorize countries.
    update = ()->
        # Create mapping of iso3 to data selected value and set min and max.
        min = null
