[crxpandion]

Thanks to Apple I will never have to re-derive first order finite difference formulas!

[ontoillogical]

Is it me or is there a mistake in the cited part of that patent too:

"where d(FI[n],FO[n]) is the squared Euclidean distance between the fingers"

The formula that is then given is under a square root, i.e. it is the Euclidean distance NOT the squared Euclidean distance.