conditional fill in d3.js for area chart

Question

I have an area graph (supposed to represent a time series). I want to color the graph based on the y value such that for regions where the y > c it is one color and for the are

Answer 1

Change the way you add the areas to something like

    vis.selectAll("path").data(mpts).enter().append("svg:path")
        .attr("class", "area")
        .attr("d", area)
        .attr("fill", function(d) { return (d.val > c ? "orange" : "yellow"); });