I am trying to implement:
dtGroupedBy.Compute(\"sum(POWER)\",dvv.RowFilter);
It results of an error:
Invalid usage
Compute method supports expressions and they support the CONVERT function that you could use inside of the expression.
CONVERT function
For example, you could calculate sum of the column like
MyDataTable.Compute("Sum(Convert(your column name, 'Data Type'))")