It was a bit of programming, but I thought of a solution:
– use a stackedArea
– subtract the stacked value
– set fillOpacity of the base value to zerro
– custom toolTip (add the other value)
function makeStacked(stack,base) {
if (stack.length != base.length) { alert('makeStacked: '+stack.length+' != '+base.length); return stack; }
var stacked = [];
for (var i = 0; i < stack.length; i++) {
stacked[i] = stack[i];
stacked[i].y = stack[i].y - base[i].y;
}
return stacked;
}