REGR_SLOPE

Description

Returns the slope of the linear regression line for non-null pairs in a group.

Syntax

REGR_SLOPE(<y>, <x>)

Parameters

Parameter	Description
<y>	The dependent variable. Supported type: Double.
<x>	The independent variable. Supported type: Double.

Return Value

Returns a Double value representing the slope of the linear regression line. If there are no rows in the group, or all rows contain NULLs for the expressions, the function returns NULL.

Examples

-- setup
CREATE TABLE test_regr_slope (
  `id` int,
  `x` int,
  `y` int
) DUPLICATE KEY (`id`)
DISTRIBUTED BY HASH(`id`) BUCKETS AUTO
PROPERTIES (
  "replication_allocation" = "tag.location.default: 1"
);

-- Insert example data
INSERT INTO test_regr_slope VALUES
(1, 18, 13),
(2, 14, 27),
(3, 12, 2),
(4, 5, 6),
(5, 10, 20);

SELECT REGR_SLOPE(y, x) FROM test_regr_slope;

Calculate the linear regression slope of x and y.

+--------------------+
| REGR_SLOPE(y, x)   |
+--------------------+
| 0.6853448275862069 |
+--------------------+

SELECT REGR_SLOPE(y, x) FROM test_regr_slope where x>100;

When there are no rows in the group, the function returns NULL.

+------------------+
| REGR_SLOPE(y, x) |
+------------------+
|             NULL |
+------------------+