Categories:

Aggregate Functions (Linear Regression) , Window Functions

REGR_INTERCEPT

Returns the intercept of the univariate linear regression line for non-null pairs in a group. It is computed for non-null pairs using the following formula:

AVG(y)-REGR_SLOPE(y,x)*AVG(x)

Where x is the independent variable and y is the dependent variable.

Syntax

Aggregation function

REGR_INTERCEPT(y, x)

Window function

REGR_INTERCEPT(y, x) OVER ( [ PARTITION BY <expr3> ] )

Arguments

y

The dependent variable. This must be an expression that can be evaluated to a numeric type.

x

The independent variable. This must be an expression that can be evaluated to a numeric type.

expr3

This is the optional expression used to group rows into partitions.

Important

Note the order of the arguments; the dependent variable is first.

Usage Notes

  • DISTINCT is not supported for this function.

  • When used as a window function:

    • This function does not support:

      • ORDER BY sub-clause in the OVER() clause.

      • Window frames.

Examples

create or replace table aggr(k int, v decimal(10,2), v2 decimal(10, 2));
insert into aggr values(1, 10, null);
insert into aggr values(2, 10, 11), (2, 20, 22), (2, 25,null), (2, 30, 35);
select k, regr_intercept(v, v2) from aggr group by k;

---+-----------------------+
 k | regr_intercept(v, v2) |
---+-----------------------+
 1 | [NULL]                |
 2 | 1.154734411           |
---+-----------------------+