REGR_SXY

Calculates the linear regression coefficient for the sum of x*y where x and y are not null.

Parameter	Type	Description
`ys`	decimal, double	the independent variable.
`xs`	decimal, double	The dependent variable

Returns: decimal

query:

SELECT REGR_SXY(flux, time_bjd_2454833)
  FROM tabbysstarflux

result:

regr_sxy
39,390.75