Application.DVar (Access)

Estimates the variance across a sample in a specified set of records (a domain).

For example, you could use the DVar function to calculate the variance across a set of students' test scores. If domain refers to fewer than two records, or if fewer than two records satisfy criteria, the DVar functions return a Null, indicating that a variance can't be calculated. Whether you use the DVar function in a macro, module, query expression, or calculated control, you must construct the criteria argument carefully to ensure that it will be evaluated correctly. You can use the DVar function to specify criteria in the Criteria row of a select query, in a calculated field expression in a query, or in the Update To row of an update query.

DVar (Expr, Domain, Criteria)

=DVar("[Freight]", "Orders", "[ShipRegion] = 'CA'")

Arguments

The following arguments are required:

Expr (String) - An expression that identifies the numeric field on which you want to find the variance. It can be a string expression identifying a field from a table or query, or it can be an expression that performs a calculation on data in that field. In expr, you can include the name field in a table, a control on a form, a constant, or a function. If expr includes a function, it can be either built-in or user-defined, but not another domain aggregate or SQL aggregate function. Any field included in expr must be a numeric field.

Domain (String) - A string expression identifying the set of records that constitutes the domain. It can be a table name or a query name for a query that does not require a parameter.

Optional arguments

The following argument is optional

Criteria (String) - An optional string expression used to restrict the range of data on which the DVar function is performed. For example, criteria is often equivalent to the WHERE clause in an SQL expression, without the word WHERE. If criteria is omitted, the DVar function evaluates expr against the entire domain. Any field that is included in criteria must also be a field in domain; otherwise, the DVar function returns a Null.