REGR_R2

Calculates the linear regression R-squared coefficient for goodness of fit of the linear regression 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_R2(flux, time_bjd_2454833)
  FROM tabbysstarflux

result:

regr_r2
0.8