R package implementing multitaper spectral estimation techniques used in time series analysis. In general the up-to-date version is on CRAN.
https://CRAN.R-project.org/package=multitaper
General build instructions:
Note:
Please see the documentation for your Linux distribution, Xcode (or Fink) for Mac, or Rtools, currently maintained by Duncan Murdoch, on CRAN.
https://cran.r-project.org/bin/windows/Rtools/
** Note: I uploaded the latest version in Oct. 2020 after checking --as-cran with the current release version of R. Please consult CRAN policy for submitting packages.