viz2").append("svg").attr("width",width+margin.left+margin.right).attr("height",height).append("g").attr("transform","translate("+margin.left+","+margin.top+")");

// read data
dataVST = data.jsonVST;
all_x = dataVST.map(function(a){return a.x?a.x:0;}), all_y = dataVST.map(function(a){return a.y?a.y:0;});


// Add X axis
x=d3.scaleLinear().domain([Math.floor(Math.min.apply(null,all_x)),Math.ceil(Math.max.apply(null,all_x))]).range([0,width]),y=d3.scaleLinear().domain([0,Math.ceil(Math.max.apply(null,all_y))