How you set a fixed x-axis with dynamic data?

Hi,

I am using the LineMarkSeries and I am feeding the data parameter with a new object (i.e. {x: cnt; y: getData()} ) and I am trying to get a fixed axis in the range from 0 to 20. However, it seems a bit difficult since the dynamic data is creating a new object containing new data points to be rendered on the graph. Does anyone know how I can fix this issue?

Thanks!