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Version: Java (Groovy)

AggSortedLast

AggSortedLast returns an aggregator that sorts a table in descending order and then computes the first value, within an aggregation group, for each input column.

note

AggSortedLast will produce the same results as a sort operation followed by AggLast.

Syntax​

AggSortedLast(sortColumn, pairs...)
AggSortedLast(sortColumns, pairs...)

Parameters​

ParameterTypeDescription
sortColumnString

The column to sort by.

pairsString...

The input/output column names for calculations.

  • "X" will output the last value in the X column for each group.
  • "Y = X" will output the last value in the X column for each group and rename it to Y.
  • "X, A = B" will output the last value in the X column for each group and the last value in the B column while renaming it to A.
sortColumnsCollection<? extends String>

The sort column names.

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 sorts the table in descending order and then computes the first value, within an aggregation group, for each input column.

Examples​

In this example, AggSortedLast returns the last Y value as sorted by Z and grouped by X.

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

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "N", "O", "P", "N", "P", "N", "", "Q", "O"),
    intCol("Z", 3, 2, 1, 1, 3, 1, 4, 1, 2),
)

result = source.aggBy([AggSortedLast("Z", "Y")], "X")

In this example, AggSortedLast returns the last Y value (renamed to Z), as sorted by Z and grouped by X.

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

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "N", "O", "P", "N", "P", "N", "", "Q", "O"),
    intCol("Z", 3, 2, 1, 1, 3, 1, 4, 1, 2),
)

result = source.aggBy([AggSortedLast("Z", "Z = Y")], "X")

In this example, AggSortedLast returns the last Y string and last Z integer, as sorted by Z and grouped by X.

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

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "N", "O", "P", "N", "P", "N", "", "Q", "O"),
    intCol("Z", 3, 2, 1, 1, 3, 1, 4, 1, 2),
)

result = source.aggBy([AggSortedLast("Z", "Y", "Z")], "X")

In this example, AggSortedLast returns the last Z integer, as sorted by Z and grouped by X and Y.

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

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "N", "O", "P", "N", "P", "N", "", "Q", "O"),
    intCol("Z", 3, 2, 1, 1, 3, 1, 4, 1, 2),
)

result = source.aggBy([AggSortedLast("Z", "Z")], "X", "Y")

In this example, AggSortedLast returns the last Y string, and AggMax returns the maximum Z integer, as sorted by Z and grouped by X.

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

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "N", "O", "P", "N", "P", "N", "", "Q", "O"),
    intCol("Z", 3, 2, 1, 1, 3, 1, 4, 1, 2),
)

result = source.aggBy([AggSortedLast("Z", "SortedLastY = Y"),AggMax("MaxZ = Z")], "X")