viewof svg_f = {
const margin = { top: 20, right: 20, bottom: 40, left: 50 };
const width = 350;
const height = 350;
const innerWidth = width - margin.left - margin.right;
const innerHeight = height - margin.top - margin.bottom;
const svg = d3.create("svg")
.attr("width", width)
.attr("height", height);
const g = svg.append("g")
.attr("transform", `translate(${margin.left},${margin.top})`);
const xScale = x.range([0, innerWidth]);
const yScale = y.range([innerHeight, 0]);
const radiusScale = d3.scaleSqrt()
.domain(d3.extent(iris, d => d.area_petalo))
.range([2, 10]);
g.append("g")
.attr("transform", `translate(0,${innerHeight})`)
.call(d3.axisBottom(xScale));
g.append("g")
.call(d3.axisLeft(yScale));
g.selectAll("circle")
.data(iris)
.enter()
.append("circle")
.attr("cx", d => xScale(d.longitud_sepalo))
.attr("cy", d => yScale(d.longitud_petalo))
.attr("r", d => radiusScale(d.area_petalo))
.attr("fill", d => color(d.area_petalo))
.attr("opacity", 0.8);
return svg.node();
}