REGR_SLOPE() GROUP BY ...

All functions > GROUP BY > REGR_SLOPE() GROUP BY ...

Returns the slope of the linear regression line fitted to (x, y) pairs.

Syntax

REGR_SLOPE(expr_y, expr_x)
 [ FILTER (WHERE condition) ]
  [ GROUP BY feature [, feature ...] ]

REGR_SLOPE(expr_y, expr_x)
 [ FILTER (WHERE condition) ]
  [ GROUP BY feature [, feature ...] ]

Notes

• Equivalent to COVAR_POP(y, x) / VAR_POP(x)
• NULL values in either expression are excluded from the calculation
• Returns NULL if VAR_POP(x) is zero or fewer than 2 non-NULL pairs exist

Examples

SELECT
    -- Regression slope for y = 2x
    f1 := ZIP(ARRAY(1, 2, 3) AS x, ARRAY(2, 4, 6) AS y).TRANSFORM(
        SELECT REGR_SLOPE(y, x)
    ).UNWRAP_ONE()
;