Specifications

CHAPTER 24 DataWindow Expression and InfoMaker Functions
Users Guide 745
Return value Double. Returns the standard deviation for column.
Usage If you specify range, StDevP returns the standard deviation for column within
range. If you specify DISTINCT,
StDevP returns an estimate of the standard
deviation for the distinct values in column, or if you specify expresn, the
estimate of the standard deviation of the rows in column where the value of
expresn is distinct.
For graphs and OLE objects, you do not select the range when you call the
function. The range has already been determined by the Rows setting on the
Data tab page (the Range property), and the aggregation function uses that
range. Settings for Rows include the following:
• For the Graph or OLE presentation style, Rows is always All.
• For Graph controls, Rows can be All, Page, or Group.
• For OLE controls, Rows can be All, Current Row, Page, or Group. The
available choices depend on the layer the control occupies.
Estimating or calculating actual standard deviation StDevP assumes that
the values in column are the values in all the rows in the column in the database
table. If you did not select all rows in the column in the
SELECT statement, use
StDev to compute an estimate of the standard deviation of a sample.
Not in validation rules or filter expressions You cannot use this or other
aggregate functions in validation rules or filter expressions.
Using an aggregate function cancels the effect of setting Retrieve Rows As
Needed in the painter. To do the aggregation, a report always retrieves all rows.
Examples These examples all assume that the SELECT statement retrieved all rows in the
database table.
StDevP is intended to work with a full set of data, not a subset.
This expression returns the standard deviation of the values in the column
named salary:
StDevP(salary)
DISTINCT
(optional)
Causes StDevP to consider only the distinct values in column when
determining the standard deviation. For a value of column, the first
row found with the value is used and other rows that have the same
value are ignored.
expresn
(optional)
One or more expressions that you want to evaluate to determine
distinct rows. Expresn can be the name of a column, a function, or
an expression.
Argument Description