col_max: Get the column name of the max/min number each row

In hope-data-science/tidyfst: Tidy Verbs for Fast Data Manipulation

Get the column name of the max/min number each row

Description

For a data.frame with numeric values, add a new column specifying the column name of the first max/min value each row.

Usage

col_max(.data, ..., .name = "max_col")

col_min(.data, ..., .name = "min_col")

Arguments

.data	A data.frame with numeric column(s)
...	Variables for screening, could receive what 'select_dt' receives. When starts with '-'(minus symbol) or '!', return the negative columns.
.name	The column name of the new added column

Value

A data.table

References

https://stackoverflow.com/questions/17735859/for-each-row-return-the-column-name-of-the-largest-value

Examples

set.seed(199057)
DT <- data.table(matrix(sample(10, 100, TRUE), ncol=10))
DT
col_max(DT)
col_max(DT,V1:V3)
col_max(DT,.name = "max_col_name")
col_min(DT)
col_min(DT,2:4)

col_max(iris)

hope-data-science/tidyfst documentation built on Sept. 23, 2024, 8:05 p.m.