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Version: Java (Groovy)

How to sort table data

Sorting is a common operation in data analysis, and Deephaven makes it easy to sort data in a variety of ways. This guide will show you how to sort table data programmatically.

tip

You can also sort columns by right-clicking the column header in the UI.

sort and sortDescending​

You can sort table data programmatically by using the sort and sortDescending methods:

source = newTable(stringCol("Letter", "A", "B", "A", "B", "B", "A"), intCol("Number", 6, 6, 1, 3, 4, 4), stringCol("Color", "red", "blue", "orange", "purple", "yellow", "pink"))

resultSort = source.sort("Letter")
resultSortDesc = source.sortDescending("Letter")

Given a column name to order the data by, sort returns a new table with the data sorted in ascending (A-Z) order, and sortDescending returns a new table with the data sorted in descending (Z-A) order.

Sorting by multiple columns​

Both sort and sortDescending can sort multiple columns at once. For example, here we will sort the table from the previous example by our Letter column, then the Number column.

resultSort = source.sort("Letter", "Number")
resultSortDesc = source.sortDescending("Letter", "Number")

Complex sorts​

The sort method can be used to sort multiple columns in different directions. For example, we can sort by Letter in ascending order, then by Number in descending order.

sortColumns = [
    SortColumn.asc(ColumnName.of("Letter")),
    SortColumn.desc(ColumnName.of("Number"))
]

result = source.sort(sortColumns)

This is simpler than invoking both methods to accomplish the same result:

result = source.sort("Letter").sortDescending("Number")

restrictSortTo​

The restrictSortTo method allows you to restrict the columns that can be sorted via the UI. This is useful if you want to prevent yourself or other users from accidentally performing expensive sort operations as you interact with tables in the UI. For example, we can restrict sorting to the Letter column:

table = source.restrictSortTo("Letter")

Now, we can still sort by Letter, but attempting to sort by Number will result in an error:

tSorted = table.sort("Number")