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Version: Java (Groovy)

AggMax

AggMax returns an aggregator that computes the maximum value, within an aggregation group, for each input column.

Syntax​

AggMax(pairs...)

Parameters​

ParameterTypeDescription
pairsString...

The source column(s) for the calculations.

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

Examples​

In this example, AggMax returns the maximum Y value as grouped by X.

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

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([AggMax("Y")], "X")

In this example, AggMax returns the maximum Y value (renamed to Z), as grouped by X.

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

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([AggMax("Z = Y")], "X")

In this example, AggMax returns the maximum Y string and maximum Number integer as grouped by X.

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

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([AggMax("Y", "Number")], "X")

In this example, AggMax returns the maximum Number integer, as grouped by X and Y.

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

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([AggMax("Number")], "X", "Y")

In this example, AggMax returns the maximum Number integer, and AggLast returns the last Number integer, as grouped by X.

import static io.deephaven.api.agg.Aggregation.AggMax
import static io.deephaven.api.agg.Aggregation.AggLast

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([AggMax("MaxNumber = Number"),AggLast("LastNumber = Number")], "X")