`r_std(C;S)`

Returns the standard deviation of values across a given set of columns.

Function type

Vector only

Syntax

r_std(C;S)

Input

Argument Type Description

Argument	Type	Description
`C`	integer or decimal	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. N/A values in `C` are ignored.
`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).

C

integer or decimal

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.

N/A values in C are ignored.

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).

Return Value

For each row of the table, r_std returns a decimal value corresponding to the standard deviation of the non-N/A values in the columns specified by C.

If all the values in the columns specified by C are N/A, the result is N/A.

Sample Usage


`c1`	`c2`	`c3`	`c4`	`r_std(;)`	`r_std(c1 c2;)`
2	5	7	2	2.4494897	2.1213203
7	7	4	1	2.8722813	0
NA	0	9	3	4.5825757	NA
NA	NA	NA	NA	NA	NA