function onMouseMoveArea (d) {
let svg = document.getElementById(graphName)
let x = d3.mouse(svg)[0] - margin.left
let y = (svg.getBoundingClientRect().width - margin.left - margin.right)/16.0
let mouseOverYearIndex = Math.floor((Math.floor(x/y) + 1 )/2)
let year = dataTotalFundingPerc[mouseOverYearIndex]['launch_year']
let currentYearPercentage
switch(d3.select(graphID).attr("data-dataset")) {
case '0':
currentYearPercentage =
(dataNumOfAllProjectsPerc[mouseOverYearIndex][this.dataset.tooltip]*100).toFixed(2)+"%";
break;
case '1':
currentYearPercentage =
(dataNumOfSuccessfulProjectsPerc[mouseOverYearIndex][this.dataset.tooltip]*100).toFixed(2)+"%";
break;
case '2':
currentYearPercentage =
(dataTotalFundingPerc[mouseOverYearIndex][this.dataset.tooltip]*100).toFixed(2)+"%";
break;
default:
}
d3.select("#rectYearHighlight")
.attr("x", margin.left-5+y*2*mouseOverYearIndex)
.style("visibility", "visible");
let tooltipText = this.dataset.tooltip + '\n' + currentYearPercentage + ' in ' + year;
switch(d3.select(graphID).attr("data-dataset")) {
case '0':
tooltipText += "\n" + (dataNumOfAllProjects[mouseOverYearIndex][this.dataset.tooltip]) + " projects launched";
break;
case '1':
tooltipText += "\n" + (dataNumOfSuccessfulProjects[mouseOverYearIndex][this.dataset.tooltip]) + " projects funded";
break;
case '2':
tooltipText += "\n" + "$" + d3.format(",.0f")(dataTotalFunding[mouseOverYearIndex][this.dataset.tooltip]);
break;
default:
}
tooltip.text(tooltipText)
return tooltip.style("top", (d3.event.pageY+20)+"px").style("left",(d3.event.pageX+10)+"px");
}