The GetCorrelation( obj1, obj2 ) command returns the correlation coefficient between the quantities-with-error obj1 and obj2.

The returned correlation is in the range $\mathrm{-1}..1$.

If obj1 and obj2 are the same, $1$ is returned.

If no correlation is defined between obj1 and obj2 (with SetCorrelation), $0$ is returned.

If either or both of the quantities-with-error obj1 and obj2 have functional dependence on other quantities-with-error, Covariance is used to calculate their relative covariance, which is then converted to the correlation coefficient.

The relationship between the covariance $u\left(y_1\,y_2\right)$ and correlation $r\left(y_1\,y_2\right)$ is

where $u\left(y_1\right)$ and $u\left(y_2\right)$ are the errors in $y_1$ and $y_2$.

$\mathrm{with}\left(\mathrm{ScientificConstants}\right)\:$

$\mathrm{with}\left(\mathrm{ScientificErrorAnalysis}\right)\:$

$\mathrm{GetCorrelation}\left(\mathrm{Constant}\left(h\right)\,\mathrm{Constant}\left(R\right)\right)$

$\mathrm{-0.010}$