particles1 = {
let chartHolder = d3.select(document.createElement("div"));
chartHolder.attr("style", "height: 420px");
let myChart = d3X3d.chart
.particlePlot()
.colors(colors)
.mappings({x: "ridge", y: "nub", z: "crack", size: "density", color: "weight"})
.width(width)
.height(height);
chartHolder.datum(pollenData).call(myChart);
return chartHolder.node();
}