`r_over(C;S;A;X)`

Returns the result of evaluating the expression X for each value in the specified columns. (Available as of version 15.21)

Function type

Vector only

r_over(C;S;A;X)

Argument	Type	Description
`C`	any	A space- or comma-separated list of column names `C` may also be a string expression (in single quotes) constituting a pattern for matching columns. For instance, `'foo*'` specifies all columns that begin with "foo". If `C` is omitted, the values in all of the columns are included. Note: The columns specified by `C` must be either all numeric (integer and decimal) or all text.
`S`	integer	A boolean column or an expression in `rcv_`/`rcn_`/`rct_` which determines whether or not that column is selected to be included in the calculation. See System variables for more information about `rcv_`/`rcn_`/`rct_`. If `S` is omitted, all columns will be considered by the function (subject to any prior column selections).
`A`	any	If you use the special variable `rca_` in the `X` argument, `A` is the initializing argument of `rca_`.
`X`	any	`X` is an expression that is used to transform the value or name of each of the selected columns. Note: Use the system variables `rcv_`, `rcn_`, and `rct_` to reference the column value, name, and type, respectively. `X` may also reference the special variable `rca_`, which takes on, for each column in succession, the result of the evaluation at the previous column processed for that row.

For each row of the table, r_over calculates the expression X for the columns selected in C.

For example, r_over(;rct_='f';0.0;rca_+rcv_^2) is the sum of squares of all floating-point columns in the table.