CumMin
CumMin calculates a cumulative minimum in an updateBy table operation.
Syntax
CumMin(pairs...)
Parameters
| Parameter | Type | Description |
|---|---|---|
| pairs | String... | The column(s) to be operated on. These can include expressions to rename the output columns (e.g., |
Returns
An UpdateByOperation to be used in an updateBy table operation.
Examples
The following example performs an updateBy on the source table using the CumMin operation. No grouping columns are given, so the cumulative minimum is calculated across all rows of the table.
source = emptyTable(25).update("Letter = (i % 2 == 0) ? `A` : `B`", "X = randomInt(0, 25)")
result = source.updateBy(CumMin("MinX = X"), "Letter")
- source
- result
The following example builds on the previous by specifying Letter as the grouping column. Thus, the cumulative minimum is calculated for each unique letter.
source = emptyTable(25).update("Letter = (i % 2 == 0) ? `A` : `B`", "X = randomInt(0, 25)")
result = source.updateBy(CumMin("MinX = X"), "Letter")
- source
- result
The following example builds on the previous by calculating the cumulative minimum of two different columns using the same UpdateByOperation.
source = emptyTable(25).update("Letter = (i % 2 == 0) ? `A` : `B`", "X = randomInt(0, 25)", "Y = randomInt(10, 30)")
result = source.updateBy(CumMin("MinX = X", "MinY = Y"), "Letter")
- source
- result
The following example builds on the previous by grouping on two columns instead of one. Each group is defined by a unique combination of letter and boolean in the Letter and Truth columns, respectively.
source = emptyTable(25).update("Letter = (i % 2 == 0) ? `A` : `B`", "Truth = randomBool()", "X = randomInt(0, 25)", "Y = randomInt(10, 30)")
result = source.updateBy(CumMin("MinX = X", "MinY = Y"), "Letter", "Truth")
- source
- result