## Name

The REGR Family of Functions

## Synopsis

SQL2003 defines a family of functions, having names beginning with REGR_, that relate to different aspects of linear regression. The functions work in the context of a least-squares regression line.

## SQL2003 Syntax

Following is the syntax and a brief description of each REGR_ function:

REGR_AVGX`(` `dependent`, `independent` `)`

Averages (as in AVG( `x` )) the `independent` variable values.

REGR_AVGY`(` `dependent`, `independent` `)`

Averages (as in AVG( `y` )) the `dependent` variable values.

REGR_COUNT`(` `dependent`, `independent` `)`

Counts the number of non-NULL number pairs.

REGR_INTERCEPT`(` `dependent`, `independent` `)`

Computes the y-intercept of the regression line.

REGR_R2`(` `dependent`, `independent` `)`

Computes the coefficient of determination.

REGR_SLOPE`(` `dependent`, `independent` `)`

Computes the slope of the regression line.

REGR_SXX`(` `dependent`, `independent` `)`

Sums the squares of the independent variable values.

REGR_SXY`(` `dependent`, `independent` `)`

Sums the products of each pair of values.

REGR_SYY`(` `dependent`, `independent` `)`

Sums the squares of the dependent variable values.

The REGR_ functions only work on number pairs containing two non-NULL values. Any number pair with one or more NULL values will be ignored.

## DB2 and Oracle

DB2 and Oracle support the SQL2003 syntax for all REGR_ functions. In addition, DB2 allows the shortened name REGR_ICPT in place of REGR_INTERCEPT.

Oracle supports the following analytic syntax:

`REGR_`function` ( `dependent`, `independent` ) OVER (`window_clause`)`

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