This is a GREAT addition to the Telerik GridViews. I had to declare a different function to serve as the computation function since it was possible that SUM(column) could return 0 in the divisor, and in those cases I wanted to return 0 as the final value. I simply added a function like this:
(bottom != 0) ? top / bottom : 0; }
Then I added the grid column aggregate like so:
AggregationExpression = detail => SafeDivideReturnZero((
)detail.Sum(m => m.value1), (
)detail.Sum(m => m.value2)),
It worked exactly like I needed it to. Thanks again for your assistance.