- This R package requires at least GNU Scientific Library (GSL; M. Galassi et al., 2016) version 2.5 - If you want to install this package under Windows by source or under Linux or MacOS, please install first GSL (https://www.gnu.org/software/gsl/) for example from http://gnu.mirrors.hoobly.com/gsl/ - Below are some instructions for installing GSL under Linux and MacOS. An installation on Windows by source is rather complicated because of the fact that GSL version 2.5 is needed. For this version there are no installers yet. Note: Terminal commands are denoted with a dollar sign ($). - You might as well test whether you can run the example: https://www.gnu.org/software/gsl/manual/html_node/An-Example-Program.html by copying the code into a c-file (here example.c) and compiling and linking by $ gcc -Wall -I/usr/local/include -c example.c $ gcc -L/usr/local/lib example.o -lgsl -lgslcblas -lm after you installed GSL. ----------------- Linux users: install the GSL library with the usual commands in the terminal (assuming you unzipped the gsl in the Downloads folder of your home directory): $ cd Downloads/gsl-2.5 $ ./configure $ make $ make check and if there are no errors so far $ sudo make install If the error "libgsl.so.23: cannot open shared object file: No such file or directory" occurs while installing the rtmpt package or testing the GSL example above, run $ sudo ldconfig -v in the terminal as well. ----------------- MacOS users: Install Homebrew (https://brew.sh/) Install GSL via Homebrew using "brew install gsl" Install Xcode from the App Store and then install the Command Line Tools using "xcode-select --install" If you use macOS Mojave, make sure to also run the following command: $ open /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg If you encouter probelms, you might also have to install gcc6 or another gcc version. Try "brew install gcc".