This code will index against the first value of a series of a line chart. For example, the first value will always be 100%, then the subsequent values are displayed as a percentage of the initial value.
An example from the federal reserve bank of dallas below.
widget.on('processresult', function(w,e) {
// indexed against first value first series
var s = e.result.series[0].data;
var ty = 0;
var t0 = s[0].y;
for (var i = 0 ; i < s.length ; i++) {
ty = s[i].y /= t0;
}
/*
If you have more than 1 series copy the code above starting at the comment "// indexed against first value first series" and relable each variable by for example adding a 1 after each variable. Also change the 0 in "e.result.series[0].data" to the relevant series.
*/
});