Specifications

CHAPTER 24 DataWindow Expression and InfoMaker Functions
Users Guide 743
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 StDev assumes that
the values in column are a sample of the values in the rows in the column in the
database table. If you selected all the rows in the column in the report’s
SELECT statement, use StDevP to compute the standard deviation of the
population.
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 did not retrieve all the
rows in the database table.
StDev is intended to work with a subset of rows,
which is a sample of the full set of data.
This expression returns an estimate for standard deviation of the values in the
column named salary:
StDev(salary)
This expression returns an estimate for standard deviation of the values in the
column named salary in group 1:
StDev(salary for group 1)
This expression returns an estimate for standard deviation of the values in
column 4 on the page:
StDev(#4 for page)
This expression entered in the Value box on the Data tab page in the graph’s
property sheet returns an estimate for standard deviation of the values in the
qty_used column in the graph:
StDev(qty_used for graph)