The OPAL Discussion Forum

[Nicole Neveu <nneveu AT hawk.iit.edu>]

Hi OPAL'ers, 

What is the equation for xpx (column 21) in the stat file?

When I calculate xrms and pxrms, (using the h5 file and math definitions), the numbers match exactly. 

I thought the calculation would be similar for the correlation term. Something like:  

correlation = ( (np.sum(x*px)/npt) - (np.sum(x)/npt)*(np.sum(px)/npt) )

However, when I do this calculation, it does not match the xpx value listed in the stat file. 

Do I need to divide by xrms? What part of the equation am I missing? 

Thanks!

Nicole