Plotting the ASCII character set.
On Sat, 3 Jul 2021 09:40:28 +0200
Ivan Krylov <krylov.r00t at gmail.com> wrote:
Hello Rolf Turner, On Sat, 3 Jul 2021 14:02:59 +1200 Rolf Turner <r.turner at auckland.ac.nz> wrote:
Can anyone suggest how I might get my plot_ascii() function working again? Basically, it seems to me, the question is: how do I persuade R to read in "\260" as "\ub0" rather than "\xb0"?
Part of the problem is that the "\xb0" byte is not in ASCII, which covers only the lower half of possible 8-bit bytes. I guess that the strings containing bytes with highest bit set used to be interpreted as Latin-1 on your machine, but now get interpreted as UTF-8, which changes their meaning (in UTF-8, the highest bit being set indicates that there will be more bytes to follow, making the string invalid if there is none). The good news is, since it's Latin-1, which is natively supported by R, there are even multiple options: 1. Mark the string as Latin-1 by setting Encoding(a) <- 'latin1' and let R do the re-encoding if and when Pango asks it for a UTF-8-encoded string. 2. Decode Latin-1 into the locale encoding by using iconv(a, 'latin1', '') (or set the third parameter to 'UTF-8', which would give almost the same result on a machine with a UTF-8 locale). The result is, again, a string where Encoding(a) matches the truth. Explicitly setting UTF-8 may be preferable on Windows machines running pre-UCRT builds of R where the locale encoding may not contain all Latin-1 characters, but that's not a problem for you, as far as I know. For any encoding other than Latin-1 or UTF-8, option (2) is still valid. I have verified that your example works on my GNU/Linux system with a UTF-8 locale if I use either option.
Thanks Ivan. That solves most of the problem, but there are still glitches. I get a plot OK, but a substantial number of the characters are displayed as a wee rectangle containing a 2 x 2 array of digits such as
0 0 8 0
Also note that there is a bit of difference between the results of using
Encoding() and the results of using iconv(). E.g. if I do
a <- "\x80"
b <- iconv(a,"latin1","UTF-8")
Encoding(a) <- "latin1"
then when I type "a" I get the Euro symbol "?", but when I type "b"
I get the string "\u0080".
But that doesn't really matter. More problematic is the fact that if I
do either
plot(0,0,type="n",xlim=c(0,1),ylim=c(0,1),ann=FALSE,axes=FALSE)
text(0.5,0.5,labels=a,cex=6)
or
plot(0,0,type="n",xlim=c(0,1),ylim=c(0,1),ann=FALSE,axes=FALSE)
text(0.5,0.5,labels=b,cex=6)
then I get wee rectangle with 0 0 8 0 arranged in a 2 x 2 array inside.
(Setting cex=6 makes it easier for my ageing eyes to see what the
digits are.)
Is there any way that I can get the Euro symbol to display correctly in
such a graphic?
Thanks.
cheers,
Rolf
Honorary Research Fellow Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276