chart = {
const svg = d3.create("svg")
.attr("height", 412)
.attr("width", 800)
let g = svg.selectAll('rect')
.data( data )
.enter()
g.append('rect')
.attr('x', margin)
.attr('y', margin)
.attr('width', d => scale(d['w']))
.attr('height', d => scale(d['h']))
.attr('stroke', 'black')
.attr('fill', 'none')
.attr('stroke-width', '1')
.attr('opacity', d => d.percent / 50)
g.append('text')
.attr('x', d => scale(d['w'])+margin-2)
.attr('y', d => scale(d['h'])+margin-2)
.attr('font-size', '8px')
.attr('text-anchor', 'end')
.text(d => `${d.w}×${d.h}:${d.percent}%`)
return svg.node()
}