Hi,

I just noticed that cross-recurrence plots created with FAN are asymmetric. As in crpxy = crp(x,y,m,t,e,'fan') is different than crpyx = crp(y,x,m,t,e,'fan'). For other methods crpxy is the same as crpyx transposed.

I thought of calculating both crpxy and crpyx with half the desired amount of neighbours (e = 0.05 instead of e = 0.1), adding them together and capping the maximum value at 1. Otherwise we're clearly not getting all the information, right?

And more generally, since for other methods crpxy = crpyx', what would happen if crpxy has horizontal lines but no vertical ones? Many RQA measures would be NaN. But applied to crpyx they wouldn't be because the horizontal lines are now vertical.

Any thoughts?

Best,

Mircea Stoica