During the feature extraction process, how could I set the param from a subset of another columns.

[lk1983823]

For example, I want to use "number_crossing_m" to a column named "x1". So I have to set a parameter "m" to it. However, for the param "m", I want to let it be the mean of another column like "x2" or the "x1" itself. How should I do it ?

Thanks.

[kohlrabi90]

Also posted in #1040.