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Version: Java (Groovy)

AggVar

AggVar returns an aggregator that computes the variance of values, within an aggregation group, for each input column.

Syntax​

AggVar(pairs...)

Parameters​

ParameterTypeDescription
pairsString...

The input/output names of the columns for the calculations.

  • "X" will output the variance of values in the X column for each group.
  • "Y = X" will output the variance of values in the X column for each group and rename it to Y.
  • "X, A = B" will output the variance of values in the X column for each group and the variance 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 variance of values, within an aggregation group, for each input column.

Examples​

In this example, AggVar returns the variance of values of Number as grouped by X.

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

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([AggVar("Number")], "X")

In this example, AggVar returns the variance of values of Number (renamed to VarNumber), as grouped by X.

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

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([AggVar("VarNumber = Number")], "X")

In this example, AggVar returns the variance of values of Number (renamed to VarNumber), as grouped by X and Y.

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

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([AggVar("VarNumber = Number")], "X", "Y")

In this example, AggVar returns the variance of values of Number (renamed to VarNumber), and AggMed returns the median Number, as grouped by X.

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

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([AggVar("VarNumber = Number"),AggMed("MedNumber = Number")], "X")