Opc.Ua.Server.AggregateCalculator.SlopedInterpolate C# (CSharp) Method

        public static DataValue SlopedInterpolate(DateTime timestamp, DataValue earlyBound, DataValue lateBound)
        {
            try
            {
                // can't interpolate if no start bound.
                if (StatusCode.IsBad(earlyBound.StatusCode))
                {
                    return new DataValue(Variant.Null, StatusCodes.BadNoData, timestamp, timestamp);
                }

                // revert to stepped if no end bound.
                if (StatusCode.IsBad(lateBound.StatusCode))
                {
                    DataValue dataValue2 = SteppedInterpolate(timestamp, earlyBound);

                    if (StatusCode.IsNotBad(dataValue2.StatusCode))
                    {
                        dataValue2.StatusCode = dataValue2.StatusCode.SetCodeBits(StatusCodes.UncertainDataSubNormal);
                    }

                    return dataValue2;
                }

                // convert to doubles.
                double earlyValue = CastToDouble(earlyBound);
                double lateValue = CastToDouble(lateBound);

                // do interpolation.
                double range = (lateBound.SourceTimestamp - earlyBound.SourceTimestamp).TotalMilliseconds;
                double slope = (lateValue - earlyValue) / range;
                double calculatedValue = slope * (timestamp - earlyBound.SourceTimestamp).TotalMilliseconds + earlyValue;

                // convert back to original type.
                DataValue dataValue = new DataValue();
                dataValue.WrappedValue = CastToOriginalType(calculatedValue, earlyBound);
                dataValue.SourceTimestamp = timestamp;
                dataValue.ServerTimestamp = timestamp;
                dataValue.StatusCode = StatusCodes.Good;

                // update status code.
                if (StatusCode.IsNotGood(earlyBound.StatusCode) || StatusCode.IsNotGood(lateBound.StatusCode))
                {
                    dataValue.StatusCode = StatusCodes.UncertainDataSubNormal;
                }

                dataValue.StatusCode = dataValue.StatusCode.SetAggregateBits(AggregateBits.Interpolated);

                return dataValue;
            }

            // exception occurs on data conversion errors.
            catch (Exception)
            {
                return new DataValue(Variant.Null, StatusCodes.BadTypeMismatch, timestamp, timestamp);
            }
        }