text: public override ValueEval Evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg0){double result;try{double d0 = NumericFunction.SingleOperandEvaluate(arg0, srcRowIndex, srcColumnIndex);result = Math.Log(d0) / NumericFunction.LOG_10_TO_BASE_e;NumericFunction.CheckValue(result);}catch (EvaluationException e){return e.GetErrorEval();}return new NumberEval(result);}