In writing class notes to teach people how to use R, I came across
a design failure of dataentry().
It seems that if you add a new value outside the bounds of an array,
dataentry() fills the intervening space with NA. That's reasonable,
but what happens if you *accidentally* entered a value outside the
bounds? There's no way to get rid of it.
Note that you are doomed once you type anyting beyond the end
of an array, even if you delete your typing before moving the
mouse out of the cell -- even then, that cell and others
between it and the end of the array will be filled with NA.
I would suggest that some mechanism be added to allow
arrays to be shortened in the data editor. It would
be generally useful, even beyond fixing typing mistakes.
(I recognize that you can shorten an array with something
like x <- X[1:132], but it should still be possible in the