regr_slope()

Aggregate. Computes the slope of the linear regression line fitted to non-NULL pairs.

Syntax

regr_slope ( dependent-expression , independent-expression )

Parameters

dependent-expression	The variable that is affected by the independent variable. The expression accepts numeric datatypes, except timestamp, bigdatetime, and interval.
independent-expression	The variable that influences the outcome. The expression accepts numeric datatypes, except timestamp, bigdatetime, and interval.

Parameters

This function converts its arguments to float, performs the computation in double-precision floating point, and returns a float. If the function is applied to an empty set, the result is NULL. The function is applied to sets of dependent-expression and independent-expression pairs after eliminating all pairs where either variable is NULL. The function is computed simultaneously during a single pass through the data. After eliminating NULL values, this computation is made, where x represents the independent variable and y represents the dependent variable:

covar_pop( x, y ) / var_pop( y )