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Version: Java (Groovy)

AggStd

AggStd returns an aggregator that computes the standard deviation of values, within an aggregation group, for each input column.

Syntax​

AggStd(pairs...)

Parameters​

ParameterTypeDescription
pairsString...

The input/output column name pairs.

  • "X" will output the standard deviation of values in the X column for each group.
  • "Y = X" will output the standard deviation of values in the X column for each group and rename it to Y.
  • "X, A = B" will output the standard deviation of values in the X column for each group and the standard deviation of values in the B value column renaming it to A.
caution

If an aggregation does not rename the resulting column, the aggregation column will appear in the output table, not the input column. If multiple aggregations on the same column do not rename the resulting columns, an error will result, because the aggregations are trying to create multiple columns with the same name. For example, in table.aggBy([agg.AggSum(“X”), agg.AggAvg(“X”)]), both the sum and the average aggregators produce column X, which results in an error.

Returns​

An aggregator that computes the standard deviation of values, within an aggregation group, for each input column.

Examples​

In this example, AggStd returns the standard deviation of values of Number as grouped by X.

import static io.deephaven.api.agg.Aggregation.AggStd

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "M", "N", "O", "N", "P", "M", "O", "P", "M"),
    intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)

result = source.aggBy([AggStd("Number")], "X")

In this example, AggStd returns the standard deviation of values of Number (renamed to Std), as grouped by X.

import static io.deephaven.api.agg.Aggregation.AggStd

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "M", "N", "O", "N", "P", "M", "O", "P", "M"),
    intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)

result = source.aggBy([AggStd("Std = Number")], "X")

In this example, AggStd returns the standard deviation of values of Number (renamed to Std), as grouped by X and Y.

import static io.deephaven.api.agg.Aggregation.AggStd

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "M", "N", "O", "N", "P", "M", "O", "P", "M"),
    intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)

result = source.aggBy([AggStd("Std = Number")], "X", "Y")

In this example, AggFirst returns the standard deviation of values of Number, and AggMed returns the median value of Number, as grouped by X.

import static io.deephaven.api.agg.Aggregation.AggStd
import static io.deephaven.api.agg.Aggregation.AggMed

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "M", "P", "O", "N", "P", "M", "O", "P", "N"),
    intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)

result = source.aggBy([AggStd("Std = Number"),AggMed("MedNumber = Number")], "X")