Aggregate. Computes the average of the independent variable of the regression line.
Syntax
REGR_AVGX( dependent-expression , independent-expression )
Parameters| 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 the function is applied to an empty set, then it 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 independent-expression:
AVG( y )
SQL/2003 SQL foundation feature (T621) outside of core SQL.
The following example calculates the average of the dependent variable, employee age.
With a GROUP BY clause:
SELECT REGR_AVGX()( Salary, ( 2008 - YEAR( BirthDate ) ) )
FROM Employees
group by depart_ID
With a window:
SELECT REGR_AVGX()( Salary, ( 2008 - YEAR( BirthDate ) ) )
FROM Employees
KEEP 10 ROWS