Currently, the mathematics functions (including the statistics functions) operate row-wise. This is of limited usefulness; there won't be very many cases in which there are so many numerical columns that calculating the standard deviation will yield anything interesting.
In order to make them more useful, the functions could have two different operation modes:
If more than one column is selected, the functions operate row-wise
If only one column is selected, the functions operate column-wise (this would make them also useful as group and summary functions)
Currently, the mathematics functions (including the statistics functions) operate row-wise. This is of limited usefulness; there won't be very many cases in which there are so many numerical columns that calculating the standard deviation will yield anything interesting.
In order to make them more useful, the functions could have two different operation modes: