/// <summary>
/// Given three of the four current channels, calculates the
/// missing channel based on the relationship IR = IA + IB + IC.
/// </summary>
/// <param name="meterInfo">Data context for accessing configuration tables in the database.</param>
public DataSeries CalculateMissingCurrentChannel()
{
Meter meter;
DataSeries missingSeries;
// If the data group does not have exactly 3 channels,
// then there is no missing channel or there is not
// enough data to calculate the missing channel
if (DefinedCurrents != 3)
{
return(null);
}
// Get the meter associated with the channels in this data group
meter = (I1 ?? I2).SeriesInfo.Channel.Meter;
if (m_i1Index == -1)
{
// Calculate I1 = IR - I2 - I3
missingSeries = IR.Add(I2.Negate()).Add(I3.Negate());
missingSeries.SeriesInfo = GetSeriesInfo(meter, m_dataGroup, "Current", "General1");
m_i1Index = m_dataGroup.DataSeries.Count;
m_dataGroup.Add(missingSeries);
}
else if (m_i2Index == -1)
{
// Calculate I2 = IR - I1 - I3
missingSeries = IR.Add(I1.Negate()).Add(I3.Negate());
missingSeries.SeriesInfo = GetSeriesInfo(meter, m_dataGroup, "Current", "General2");
m_i1Index = m_dataGroup.DataSeries.Count;
m_dataGroup.Add(missingSeries);
}
else if (m_i3Index == -1)
{
// Calculate I3 = IR - I1 - I2
missingSeries = IR.Add(I1.Negate()).Add(I2.Negate());
missingSeries.SeriesInfo = GetSeriesInfo(meter, m_dataGroup, "Current", "General3");
m_i1Index = m_dataGroup.DataSeries.Count;
m_dataGroup.Add(missingSeries);
}
else
{
// Calculate IR = I1 + I2 + I3
missingSeries = I1.Add(I2).Add(I3);
missingSeries.SeriesInfo = GetSeriesInfo(meter, m_dataGroup, "Current", "RES");
m_i1Index = m_dataGroup.DataSeries.Count;
m_dataGroup.Add(missingSeries);
}
return(missingSeries);
}
public DataGroup ToSubGroup(int startIndex, int endIndex)
{
DataGroup subGroup = new DataGroup();
foreach (DataSeries dataSeries in m_dataSeries)
{
subGroup.Add(dataSeries.ToSubSeries(startIndex, endIndex));
}
return(subGroup);
}
public static DataGroup Combine(params DataGroup[] dataGroups)
{
DataGroup combination = new DataGroup();
foreach (DataGroup dataGroup in dataGroups)
{
foreach (DataSeries dataSeries in dataGroup.DataSeries)
{
combination.Add(dataSeries);
}
}
return(combination);
}
public static DataGroup ToCycleDataGroup(DataSeries dataSeries, double frequency)
{
DataGroup dataGroup = new DataGroup();
DataSeries rmsSeries = new DataSeries();
DataSeries phaseSeries = new DataSeries();
DataSeries peakSeries = new DataSeries();
DataSeries errorSeries = new DataSeries();
int samplesPerCycle;
double[] yValues;
double[] tValues;
double sum;
DateTime cycleTime;
SineWave sineFit;
if ((object)dataSeries == null)
{
return(null);
}
// Set series info to the source series info
rmsSeries.SeriesInfo = dataSeries.SeriesInfo;
phaseSeries.SeriesInfo = dataSeries.SeriesInfo;
peakSeries.SeriesInfo = dataSeries.SeriesInfo;
errorSeries.SeriesInfo = dataSeries.SeriesInfo;
// Get samples per cycle of the data series based on the given frequency
samplesPerCycle = CalculateSamplesPerCycle(dataSeries, frequency);
// Initialize arrays of y-values and t-values for calculating cycle data
yValues = new double[samplesPerCycle];
tValues = new double[samplesPerCycle];
for (int i = 0; i <= dataSeries.DataPoints.Count - samplesPerCycle; i += samplesPerCycle)
{
// Use the time of the first data point in the cycle as the time of the cycle
cycleTime = dataSeries.DataPoints[i].Time;
sum = 0.0D;
// Copy values from the original data series into the y-value and t-value arrays
for (int j = 0; j < samplesPerCycle; j++)
{
yValues[j] = dataSeries.DataPoints[i + j].Value;
tValues[j] = (dataSeries.DataPoints[i + j].Time - cycleTime).TotalSeconds;
sum += yValues[j] * yValues[j];
}
// Use a curve fitting algorithm to estimate the sine wave over this cycle
sineFit = WaveFit.SineFit(yValues, tValues, frequency);
// Add data points to each of the cycle data series
rmsSeries.DataPoints.Add(new DataPoint()
{
Time = cycleTime,
Value = Math.Sqrt(sum / samplesPerCycle)
});
phaseSeries.DataPoints.Add(new DataPoint()
{
Time = cycleTime,
Value = sineFit.Phase
});
peakSeries.DataPoints.Add(new DataPoint()
{
Time = cycleTime,
Value = sineFit.Amplitude
});
errorSeries.DataPoints.Add(new DataPoint()
{
Time = cycleTime,
Value = tValues
.Select(sineFit.CalculateY)
.Zip(yValues, (estimate, value) => Math.Abs(estimate - value))
.Sum()
});
}
// Add a series to the data group for each series of cycle data
dataGroup.Add(rmsSeries);
dataGroup.Add(phaseSeries);
dataGroup.Add(peakSeries);
dataGroup.Add(errorSeries);
return(dataGroup);
}
