iris

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>

<body>
  <script>
    var margin = {top: 20, right:10, bottom: 20, left: 10}
    
    var width = 960 - margin.left -margin.right,
        height = 500 - margin.top - margin.bottom;
    
    var svg  = d3.select("body").append("svg")
    	.attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom).append("g")
    .attr("transform", "translate("+ margin.left + "," + margin.top +")")
    
    var x = d3.scaleLinear()
    	.range([0,width]);
    
    var y = d3.scaleLinear()
    	.range([height, 0]);
    
    var r = d3.scaleSqrt()
    	.range([2, 10]);
    
    var color = d3.scaleOrdinal(d3.schemeCategory20);
    
    var xAxis = d3.axisBottom().scale(x);
    
    var yAxis = d3.axisLeft().scale(y);
    
    var tooltip = d3.select("body").append("div")
					.attr("class", "tooltip")
					.style("opacity", 0);
    
    function scatterplot(el, data, h, w, dim, var_x, var_y, var_c, var_r){
      
      
    var svg  = d3.select("body").append("svg")
    	.attr("width", w + margin.left + margin.right)
    	.attr("height", h + margin.top + margin.bottom).append("g")
    	.attr("transform", "translate("+ margin.left + "," + margin.top +")")
    
    var x = d3.scaleLinear()
    		.range([0,width]);
    
    var y = d3.scaleLinear()
    		.range([height, 0]);
    
    var r = d3.scaleSqrt()
    		.range([2, 10]);
    
    var color = d3.scaleOrdinal(d3.schemeCategory20);
    
    var xAxis = d3.axisBottom().scale(x);
    
    var yAxis = d3.axisLeft().scale(y);
    
    var tooltip = d3.select("body").append("div")
					.attr("class", "tooltip")
					.style("opacity", 0);
      
    			x.domain(d3.extent(data, function(d) {return d. sepal_length}))
          y.domain(d3.extent(data, function(d) {return d. sepal_width}))
          r.domain(d3.extent(data, function(d) {return d. petal_length}))
          color.domain(d3.extent(data, function(d) {return d.species}))
          
          console.log(data)
          
        svg.selectAll(".dot").data(data).enter()
    				.append("circle")
    				.attr("class", "dot")
    				.attr("cx", function(d) {return x(d.sepal_length);})
    				.attr("cy", function(d) {return y(d.sepal_width);})
          	.attr("r", function(d) {return r(d.petal_length);})
    				.style("fill", function(d) {return color(d.species);})
          
        var legend = svg.selectAll(".legend")
      		.data(color.domain())
   			  .enter().append("g")
      		.attr("class", "legend")
      		.attr("transform", function(d, i) { return "translate(0," + i * 20 + ")"; });

legend.append("rect")
      		.attr("x", width - 18)
      		.attr("width", 18)
      		.attr("height", 18)
      		.style("fill", color);

legend.append("text")
      		.attr("x", width - 24)
      		.attr("y", 9)
      		.attr("dy", ".35em")
      		.style("text-anchor", "end")
      		.text(function(d) { return d; });

}
    
    d3.csv("iris.csv",function(error, data){
      
      scatterplot(d3.select("body", data))
      
      data.forEach(function(d){
        d.sepal_length = +d.sepal_length
        d.sepal_width = +d.sepal_width
        d.petal_length = +d.petal_length
        d.petal_width = +d.petal_width
 
      });
      
          
    });

</script>
</body>

https://d3js.org/d3.v4.min.js