light cleanup + adding highlighting same instance twice

public/app.js

@@ -14,6 +14,8 @@ const renderTable = () => {
 		.data(instances.filter(d => d.highlighted > 0).sort((a,b) => a.highlighted - b.highlighted), d => d.id)
 		.enter()
 		.append('tr')
+		//.exit()
+		//.remove()
 		.selectAll('td')
 		.data(d => [
 			d.instance_id, 
@@ -37,22 +39,20 @@ const renderPoints = () => {
 		.append('circle');
 
 	d3.selectAll('circle')
-		.attr('cy', (datum, index) => {
-			return yScale(datum.ninety_day_outcomes/datum.graduates*100);
-		});
+		.attr('cy', (datum, index) => yScale(datum.ninety_day_outcomes/datum.graduates*100) );
 
 	d3.selectAll('circle')
-		.attr('cx', (datum, index) => {
-			return xScale(parseTime(datum.graduation_date));
-		});
+		.attr('cx', (datum, index) => xScale(parseTime(datum.graduation_date)) );
 
 	d3.selectAll('circle')
-		.classed('highlighted', (datum, index)=>{
-			return datum.highlighted > 0
-		})
+		.classed('highlighted', (datum, index)=> datum.highlighted > 0 )
 
 	d3.selectAll('circle').on('click', (event, datum) => {
+		if(datum.highlighted === 0){
 			datum.highlighted = ++highlighted;
+		} else {
+			datum.highlighted = 0;
+		}
 		renderPoints()
 		renderTable()
 	});