Decimal Weighted Ave

Use in place of the built-in WEIGHTEDAVE aggregation to avoid tiny errors that can be introduced by floating point math.

This aggregator calculates the result by using the BigDecimal add, multiply and divide methods. It changes the column binding data type to DECIMAL, although you can change it to something else after.

An additional parameter is Weight, which is an expression that returns a decimal value. You should use new BigDecimal() for constant values or use BirtMath if you wish to perform calculations on the current data row. This value is ignored for all rows except the first.