BiostatR Blog

Install homebrew In terminal: brew install wget brew install openssl brew install  libssh2 cd ~/Downloads/ wget https://cran.r-project.org/src/contrib/git2r_0.21.0.tar.gz R CMD INSTALL --configure-args='--with-libssl-include=/opt/local/include --with-             libssl-lib=/opt/local/lib' git2r_0.21.0.tar.gz rm  git2r_0.21.0.tar.gz

To plot beautiful arrows, use the "shape" package. The syntax is very close to the syntax of arrow() in grid package. To have the end of the arrow exactly at the (x1, y1) point, use the parameter arr.adj = 1 library("shape") plot(x=c(0, 1), y=c(0,1)) segments(x0 = 0, y0 = 0.5, x1 = 1, y1 = 0.5, lty = 2) Arrows(x0 = 0.5, x1 = 0.5, y0 = 0.2, y1 = 0.5, arr.adj = 1) segments(x0 = 0.4, y0 = 0, x1 = 0.4, y1 = 1, lty = 2) Arrows(x0 = 0.2, x1 = 0.4, y0 = 0.4, y1 = 0.4, arr.adj = 1)