/// <summary>
/// New value will be integer.
/// </summary>
public static ContinuousGroupByOperation AddIntNumberOfDistinctKeys(this ContinuousGroupByOperation op, string column, RowKeyGenerator keyGenerator)
{
var id = op.Aggregators.Count.ToString("D", CultureInfo.InvariantCulture) + ":" + nameof(AddIntNumberOfDistinctKeys);
return(op.AddAggregator((aggregate, row) =>
{
var key = keyGenerator.Invoke(row);
if (key != null)
{
var hashset = aggregate.GetStateValue <HashSet <string> >(id, null);
if (hashset == null)
{
hashset = new HashSet <string>();
aggregate.SetStateValue(id, hashset);
}
if (!hashset.Contains(key))
{
hashset.Add(key);
var newValue = hashset.Count;
aggregate.ResultRow.SetValue(column, newValue);
}
}
}));
}
/// <summary>
/// New value will be double. Null values are ignored.
/// </summary>
public static ContinuousGroupByOperation AddDoubleAverageIgnoreNull(this ContinuousGroupByOperation op, string sourceColumn, string targetColumn = null)
{
var idSum = op.Aggregators.Count.ToString("D", CultureInfo.InvariantCulture) + ":" + nameof(AddDoubleAverageIgnoreNull) + ":sum";
var idCnt = op.Aggregators.Count.ToString("D", CultureInfo.InvariantCulture) + ":" + nameof(AddDoubleAverageIgnoreNull) + ":cnt";
if (targetColumn == null)
{
targetColumn = sourceColumn;
}
return(op.AddAggregator((aggregate, row) =>
{
if (!row.HasValue(sourceColumn))
{
return;
}
var newSum = aggregate.GetStateValue(idSum, 0.0d) + row.GetAs(sourceColumn, 0.0);
aggregate.SetStateValue(idSum, newSum);
var newCnt = aggregate.GetStateValue(idCnt, 0) + 1;
aggregate.SetStateValue(idCnt, newCnt);
var newValue = newSum / newCnt;
aggregate.ResultRow.SetValue(targetColumn, newValue);
}));
}
/// <summary>
/// New value will be integer.
/// </summary>
public static ContinuousGroupByOperation AddIntCount(this ContinuousGroupByOperation op, string targetColumn)
{
return(op.AddAggregator((aggregate, row) =>
{
var newValue = aggregate.ResultRow.GetAs(targetColumn, 0) + 1;
aggregate.ResultRow.SetValue(targetColumn, newValue);
}));
}
/// <summary>
/// New value will be integer.
/// </summary>
public static ContinuousGroupByOperation AddIntCountWhenNull(this ContinuousGroupByOperation op, string targetColumn, string columnToCheckForNull)
{
return(op.AddAggregator((aggregate, row) =>
{
if (!row.HasValue(columnToCheckForNull))
{
var newValue = aggregate.ResultRow.GetAs(targetColumn, 0) + 1;
aggregate.ResultRow.SetValue(targetColumn, newValue);
}
}));
}
/// <summary>
/// New value will be decimal.
/// </summary>
public static ContinuousGroupByOperation AddDecimalSum(this ContinuousGroupByOperation op, string sourceColumn, string targetColumn = null)
{
if (targetColumn == null)
{
targetColumn = sourceColumn;
}
return(op.AddAggregator((aggregate, row) =>
{
var newValue = aggregate.ResultRow.GetAs(targetColumn, 0m) + row.GetAs(sourceColumn, 0m);
aggregate.ResultRow.SetValue(targetColumn, newValue);
}));
}
/// <summary>
/// New value will be double.
/// </summary>
public static ContinuousGroupByOperation AddDoubleMin(this ContinuousGroupByOperation op, string sourceColumn, string targetColumn = null)
{
if (targetColumn == null)
{
targetColumn = sourceColumn;
}
return(op.AddAggregator((aggregate, row) =>
{
var newValue = aggregate.ResultRow.HasValue(targetColumn)
? Math.Min(aggregate.ResultRow.GetAs(targetColumn, 0.0d), row.GetAs(sourceColumn, 0.0d))
: row.GetAs(sourceColumn, 0.0d);
aggregate.ResultRow.SetValue(targetColumn, newValue);
}));
}
/// <summary>
/// Calculates the standard deviation for an aggregate.
/// https://math.stackexchange.com/questions/198336/how-to-calculate-standard-deviation-with-streaming-inputs
/// </summary>
/// <param name="op">The operation</param>
/// <param name="useEntirePopulation">If true, equivalent to STDEV.P, if false, STDEV.S</param>
/// <param name="sourceColumn">The source column.</param>
/// <param name="targetColumn">The targe column.</param>
public static ContinuousGroupByOperation AddDoubleStandardDeviation(this ContinuousGroupByOperation op, bool useEntirePopulation, string sourceColumn, string targetColumn = null)
{
if (targetColumn == null)
{
targetColumn = sourceColumn;
}
var idM2 = op.Aggregators.Count.ToString("D", CultureInfo.InvariantCulture) + ":" + nameof(AddDoubleAverageIgnoreNull) + ":m2";
var idCnt = op.Aggregators.Count.ToString("D", CultureInfo.InvariantCulture) + ":" + nameof(AddDoubleAverageIgnoreNull) + ":cnt";
var idMean = op.Aggregators.Count.ToString("D", CultureInfo.InvariantCulture) + ":" + nameof(AddDoubleAverageIgnoreNull) + ":mean";
return(op.AddAggregator((aggregate, row) =>
{
if (!row.HasValue(sourceColumn))
{
return;
}
var m2 = aggregate.GetStateValue(idM2, 0.0);
var newCount = aggregate.GetStateValue(idCnt, 0) + 1;
var mean = aggregate.GetStateValue(idMean, 0.0);
var value = row.GetAs(sourceColumn, 0.0);
var delta = value - mean;
mean += delta / newCount;
m2 += delta * (value - mean);
if (!useEntirePopulation && newCount < 2)
{
aggregate.ResultRow.SetValue(targetColumn, null);
}
else
{
var divider = useEntirePopulation
? newCount
: newCount - 1;
aggregate.ResultRow.SetValue(targetColumn, Math.Sqrt(m2 / divider));
}
aggregate.SetStateValue(idM2, m2);
aggregate.SetStateValue(idCnt, newCount);
aggregate.SetStateValue(idMean, mean);
}));
}
/// <summary>
/// New value will be decimal.
/// </summary>
public static ContinuousGroupByOperation AddDecimalAverage(this ContinuousGroupByOperation op, string sourceColumn, string targetColumn = null)
{
var id = op.Aggregators.Count.ToString("D", CultureInfo.InvariantCulture) + ":" + nameof(AddDecimalAverage);
if (targetColumn == null)
{
targetColumn = sourceColumn;
}
return(op.AddAggregator((aggregate, row) =>
{
var newSum = aggregate.GetStateValue(id, 0m) + row.GetAs(sourceColumn, 0m);
aggregate.SetStateValue(id, newSum);
var newValue = newSum / (aggregate.RowsInGroup + 1);
aggregate.ResultRow.SetValue(targetColumn, newValue);
}));
}
