datatable.rowargmax()

datatable.

rowargmax

(

*cols

)

sourcetests

Added in version 1.1.0

For each row, find the index of the largest value among the columns from cols. When the largest value occurs more than once, the smallest column index is returned.

Parameters

cols

FExpr

Input columns.

return

FExpr

f-expression consisting of one column that has the same number of rows as in cols. The column type is int64.

except

TypeError

The exception is raised when cols has non-numeric columns.

Examples

from datatable import dt, f DT = dt.Frame({"A": [1, 1, 2, 1, 2], "B": [None, 2, 3, 4, None], "C":[True, False, False, True, True]}) DT

	A	B	C
	int32	int32	bool8
0	1	NA	1
1	1	2	0
2	2	3	0
3	1	4	1
4	2	NA	1

5 rows × 3 columns

DT[:, dt.rowargmax(f[:])]

	C0
	int64
0	0
1	1
2	1
3	1
4	0

5 rows × 1 column

See Also

• rowargmin() – find the index of the smallest element row-wise.