[R] Typographical error in the documentation of function strwidth?

ALBERTO VIEIRA FERREIRA MONTEIRO
Thu, 17 Mar 2016 13:27:47 -0000

Peter Dalgaard wrote:

> I don't think so. I'll give you that it should either be the
(number of lines - 1)*spacing
> or (number of linefeeds)*spacing, but it's correct to count the height
of "M" only on the top line.
>
> -pd
>
> It is correct as written
>
Ah, ok, I see now. The "line spacing" is not the line spacing, but the
inter-line spacing plus
the height of "M":

"Note that the ?height? of a string is determined only by the number of
linefeeds ("\n") it contains: it is the (number of linefeeds - 1)
times the line spacing plus the height of "M" in the selected font.
For an expression it is the height of the bounding box as computed by plotmath.
Thus in both cases it is an estimate of how far above the final baseline the
typeset object extends. (It may also extend below the baseline.) The inter-line
spacing is controlled by cex, par("lheight") and the ?point size? (but
not the actual font in use)"

It's still confusing... Specially since there's no way to get the
inter-line spacing except by running

strheight("M\nM") - 2 * strheight("M")

Alberto Monteiro