When I run apt install r-base it provides me with a slightly out-dated version of R. When I tried to look up how to get a newer version, much of what I found did something to the file /etc/apt/source.list. The content of this file is
#deb cdrom:[Linux Mint 18.3 _Sylvia_ - Release amd64 20171124]/ xenial contrib $
Most instructions suggest appending something like
deb http://cran.rstudio.com/bin/linux/debian wheezy-cran3/
But none of the various suggestions I've read have worked--presumably either because they were for non-Mint distros or they were for outdated versions of Mint. I tried taking something that I found, like
http://cran.ma.imperial.ac.uk/bin/linux/ubuntu trusty/
and editing it with the codename that I found elsewhere which seems to be the most recent, hence making it
http://cran.ma.imperial.ac.uk/bin/linux/ubuntu sylvia/
But when I ran the update it couldn't find the repo, presumably because places that have Trusty don't necessarily have Sylvia--although maybe it didn't work for some other reason. (And I notice the UK address which probably is bad for me to be using in America, but I don't really get how I'm supposed to find an address that will have the right files.)
Since I see a number of times when this question has been asked and solutions always seem to be short-lived, applying only so long as that particular version is hosted by that particular address and is the latest version--can I ask something where the answer might have a little more longevity: In general, how do you find the right thing to add to your /etc/apt/source.list file to make this work? How do you find the right repo source (same thing as a mirror?), the current codename, and so on? (It would also be nice to have a generalized procedure for how to solve this, because I basically ran into the same problem on my old computer with a 32-bit architecture, and would like to have R running on that too without having to ask the question a second time--but presumably the specific thing and place I'll have to download for that is different.)
Copyright Notice：Content Author:「Addem」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/51414409/getting-the-latest-version-of-r-with-linux-mint