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Computes the average of the dependent variable of the regression line.
REGR_AVGY(dependent-expression, independent-expression)
REGR_AVGY(dependent-expression, independent-expression)
OVER (window-spec)
window-spec: See Syntax 2 instructions in the Usage section, below.
dependent-expression The variable that is affected by the independent variable.
independent-expression The variable that influences the outcome.
This function converts its arguments to DOUBLE, performs the computation in double-precision floating-point, and returns a DOUBLE as the result. If applied to an empty set, then REGR_AVGY returns NULL.
The function is applied to the set of (dependent-expression and independent-expression) pairs after eliminating all pairs for which either dependent-expression or independent-expression is NULL. The function is computed simultaneously during a single pass through the data. After eliminating NULL values, the following computation is then made, where y represents the dependent-expression:
AVG(y)
See "Mathematical formulas for the aggregate functions "in SQL Anywhere Server – SQL Usage.
ROLLUP and CUBE are not supported in the GROUP
BY clause with Syntax 1. DISTINCT is not supported.
Syntax 2 represents usage as a window function in a SELECT statement. As such, you can specify elements of window-spec either in the function syntax (inline), or with a WINDOW clause in the SELECT statement. For information on how to specify the window, see “Analytical functions”.
The following example calculates the average of the independent variable, employee salary. This function returns the value 49988.6232:
SELECT REGR_AVGY( Salary, ( YEAR( NOW( )) - YEAR( BirthDate ) ) )FROM Employees;
