try this, i implemented in my application, include this in your addGraph method before returning chart object
var parent = $('svg').parent().attr("id");
//add a button to your DIV and give onclick evet function
d3.select("#"+parent).append('a').attr('href',"javascript:void(0)")
.text('Sort').on("click", sortBars).html('Sort');
//sorting function
var sortOrder;
var sortBars = function(){
if( !sortOrder || sortOrder == null)
sortOrder = true;
else sortOrder = false;
var historicalBarChart11 ;
var data1 = JSON.parse(JSON.stringify(data));//cloning object
sortdata = data1[0].values;
sortdata.sort(function(a,b){
if(sortOrder)
return a["value"]-b["value"];//[1];
else
return b.value-a.value;//[1];
});
for(var i=0;i<sortdata.length;i++){
data1[0]["values"][i] = sortdata[i];
}
d3.select('svg').datum(data1).transition().duration(500).call(chart);
}