To install the master branch of the package you need to have devtools installed. If this isn't installed, then install it with:
> install.packages("devtools")
After this, you can run the following to install the package:
> library(devtools)
> devtools::install_github('mattg3004/SchistoxpkgR', build_vignettes=T)
This will build a vignette, which will take some time, so the installation of the package may take a few minutes.
After installation is complete, to view the vignette run the following:
> browseVignettes("SchistoxpkgR")