Decimal precision in ListGrid

I am trying to limit the number of decimals in a number pulled from a datasource in my SmartGWT application.

I am not sure if I should be doing so in the datasource xml file, in the listgridfield, or where I should be doing it.

I have a field in my datasource that is of type float

Is there an attribute I can use in that code to set it to a maximum of 3 decimal places? Or should it be set somehow in the ListGridField declaration?

Thanks