OK. I've worked it out.
df.withColumn('diff', col('A')-col('B'))
On Sun, May 7, 2017 at 11:49 AM, Zeming Yu <zemin...@gmail.com> wrote:
> Say I have the following dataframe with two numeric columns A and B,
> what's the best way to add a column showing the difference between the two
> columns?
>
> +-----------------+----------+
> | A| B|
> +-----------------+----------+
> |786.3199999999999| 786.12|
> | 786.12| 786.12|
> | 786.42| 786.12|
> | 786.72| 786.12|
> | 786.92| 786.12|
> | 786.92| 786.12|
> | 786.72| 786.12|
> | 786.72| 786.12|
> | 827.72| 786.02|
> | 827.72| 786.02|
> +-----------------+----------+
>
>
> I could probably figure out how to do this vis UDF, but is UDF generally
> slower?
>
>
> Thanks!
>
>
