regr_sxx()

Aggregate. Returns the sum of squares of independent expressions used in a linear regression model. Evaluates Use the statistical validity of a regression model.

Syntax

regr_sxx ( 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.

Usage

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:

regr_count( x, y ) * var_pop( x )