By: Kevin Yin
R->A calculation removed: it wasn't valid anyway. No behavior change.
Placed existing A in there directly.
cosh window -> strangely tweaked exp window: remove the discontinuity
at the border, which is wrong for a window function. If A changes in the
future, this window will be better. With the current A, you will not be
able to tell the difference on any graph. (Of course, it's not a cosh
window anymore.)
Fixes#2574