Reference > Functions reference > Aggregate functions > StDev
 

StDev

Returns the standard deviation of the sample represented by a series of non-blank values in a field.

Format 

StDev(field{;field...})

Parameters 

field - any related field, repeating field, or set of non-repeating fields; or an expression that returns a field, repeating field, or set of non-repeating fields.

Parameters in braces { } are optional.

Data type returned 

number

Originated in 

FileMaker Pro 6.0 or earlier

Description 

Field can be any of the following:

a repeating field (repeatingField).

a field in matching related records specified by (table::field), whether or not these records appear in a portal.

several non-repeating fields in a record (field1;field2;field3).

corresponding repetitions of repeating fields in a record (repeatingField1;repeatingField2;repeatingField3), if the result is returned in a repeating field with at least the same number of repeats.

several fields in the first matching record specified by (table 1::field A, table 2::field B,...). You can name a different table for each field (table 1::field A;table 2::field B...).

Equation

Notes 

When a referenced field is a repeating field, the StDev function returns the standard deviation in the first repetition fields, then the standard deviation in the second repetition fields, and so on.

Example 1 

A portal displays the related values 5, 6, 7, and 8 in a field called Scores. StDev(table::Scores) returns 1.29099444....

Example 2 

In the following examples:

Field1 contains two repetitions with values of 1 and 2.

Field2 contains four repetitions with values of 5, 6, 7, and 8.

Field3 contains four repetitions with values of 6, 0, 4, and 4.

Field4 contains one repetition with a value of 3.

StDev(Field4) results in an error because standard deviation of a single number is not defined.

StDev(Field1;Field2;Field3) returns 2.64575131..., 3.05505046..., 2.12132034..., 2.82842712... for a repeating field.

Related topics 

Functions reference (category list)

Functions reference (alphabetical list)

About formulas

About functions

Defining calculation fields

Using operators in formulas