JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//d3js.org/d3.v3.min.js"></script>

JavaScript

var size = 10;
dataset = [];
for(var y = 0; y<size; y++){
    var tempData = [size];
    for(var x = 0; x<size; x++){
        tempData[x] = 5;
    };
    dataset.push(tempData);
};

d3.select("body").append("svg")
	 .attr("width", size * 20)
   .attr("height", size * 20)
   .selectAll("rect")
   .data(dataset)
   .enter()
   .append("g")
   .selectAll("rect")
   .data(function (d,i) {return d;})
   .enter()
   .append("rect")
   .attr("x", function(d,i){
            return i*20;
   })
   .attr("y", function(d, i, j){
            return j*20;
   })
   .attr("height", 15)
   .attr("width", 15)
   .attr("fill", "green");