I created a grouped barchart in the code jsfiddle as explained here. My need is to adjust the size of the bandwidth in the X axis dynamically based on the values different than zero. For example the x axis with the value poacee to display only two value(bars) without space in between the blue and red barcharts and accordingly to adjust the bandwidth of X axis, to have size of the two elements.
code:
<!DOCTYPE html>
<meta charset="utf-8">
<!-- Load d3.js -->
<script src="https://d3js.org/d3.v4.js"></script>
<!-- Create a div where the graph will take place -->
<div id="my_dataviz"></div>
<script>
// set the dimensions and margins of the graph
var margin = {top: 10, right: 30, bottom: 20, left: 50},
width = 460 - margin.left - margin.right,
height = 400 - margin.top - margin.bottom;
// append the svg object to the body of the page
var svg = d3.select("#my_dataviz")
.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 + ")");
// Parse the Data
var data = [
{"group": "banana", "Nitrogen": "12", "normal": 1, "stress": 13},
{"group": "poacee", "Nitrogen": "6", "normal": 0, "stress": 33},
{"group": "sorgho", "Nitrogen": "11", "normal": 28, "stress": 12},
{"group": "triticum", "Nitrogen": "19", "normal": 6, "stress": 1}]
// List of subgroups = header of the csv files = soil condition here
var subgroups = ["group","Nitrogen", "normal", "stress"]
// List of groups = species here = value of the first column called group -> I show them on the X axis
// var groups = d3.map(data, function(d){return(d.group)}).keys()
var groups = ["banana", "poacee", "sorgho", "triticum"]
// Add X axis
var x = d3.scaleBand()
.domain(groups)
.range([0, width])
.padding([0.2])
svg.append("g")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(x).tickSize(0));
// Add Y axis
var y = d3.scaleLinear()
.domain([0, 40])
.range([ height, 0 ]);
svg.append("g")
.call(d3.axisLeft(y));
// Another scale for subgroup position?
var xSubgroup = d3.scaleBand()
.domain(subgroups)
.range([0, x.bandwidth()])
.padding([0.05])
// color palette = one color per subgroup
var color = d3.scaleOrdinal()
.domain(subgroups)
.range(['#e41a1c','#377eb8','#4daf4a'])
// Show the bars
svg.append("g")
.selectAll("g")
// Enter in data = loop group per group
.data(data)
.enter()
.append("g")
.attr("transform", function(d) { return "translate(" + x(d.group) + ",0)"; })
.selectAll("rect")
.data(function(d) { return subgroups.map(function(key) { return {key: key, value: d[key]}; }); })
.enter().append("rect")
.attr("x", function(d) { return xSubgroup(d.key); })
.attr("y", function(d) { return y(d.value); })
.attr("width", xSubgroup.bandwidth())
.attr("height", function(d) { return height - y(d.value); })
.attr("fill", function(d) { return color(d.key); });
</script>