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 version 

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.

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