Returns the correlation coefficient of a set of number pairs.
CORR( dependent-expression, independent-expression )
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, and performs the computation in double-precision floating point. If the function is applied to an empty set, then it returns NULL.
Both dependent-expression and independent-expression are numeric. The function is applied to the set of (dependent-expression, independent-expression) after eliminating the pairs for which either dependent-expression or independent-expression is NULL. The following computation is made:
COVAR_POP ( y, x ) / STDDEV_POP ( y ) * STDDEV_POP ( x )
where y represents the dependent-expression and x represents the independent-expression.
SQL/2003 SQL foundation feature outside core SQL.
The following example performs a correlation to discover whether age is associated with income level. This function returns the value 0.44022675645995957.
SELECT CORR( Salary, ( YEAR( NOW( ) ) - YEAR( BirthDate ) ) ) FROM Employees;
|Discuss this page in DocCommentXchange.
Send feedback about this page using email.
|Copyright © 2009, iAnywhere Solutions, Inc. - SQL Anywhere 11.0.1|