Install rcartogram package in Windows 10

Preparing R for rcartogram package in Windows 10
requires uninstalling rtools 3.3, then installing rtools 3.5 (ensure PATH is updated accordingly).
also tries to direct R to install packages under HOME/library, by editing HOME/etc/Rprofile.site
  (editing with administrator rights because HOME is under C:/Program Files).
Also, the HOME folder needs its property set (right click, security or permission to write).
1. in R, use installr package to updater()
2. update RStudio IDE; check both RStudio and R to be the latest versions
3. check Rtools 3.5 are put in the common folders C:\Rtools\bin etc
3b. check the R tools paths are in the System PATH variable (Control panel .
  Advanced System...) Ensure the order of the paths follow Rtools README.txt
  or Rtools.txt guidance
4. install.packages("devtools"), or better follow this https://cran.r-project.org/web/packages/devtools/readme/README.html
5. install fftw3 package
5b. look at HOME/library while installing fftw3 to see it's put there.
6. Ensure fftw3 bin is in the PATH variable too (previously it's under C:/msys, now elsewhere)
7. then follow this by Geoff Lee: https://raw.githubusercontent.com/Geoff99/Rcartogram/WindowsInstall/vignettes/README.WindowsInstall.Tutorial.Rmd
8. Test!