This is a Homebrew formula for PGPLOT. homebrew recently removed pgplot for a Licence issue. This is a local backup (+ minor modificaiton) of the latest pgplot formula just before being removed. You can tap this repository and install pgplot.
brew install kazuakiyama/pgplot/pgplot
Or brew tap kazuakiyama/pgplot and then brew install pgplot.
Don't forget to add paths for PGPLOT. For instance, you can add the following line to your ~/.bashrc_profile or ~/.zprofile files (and remember to source the file to update your current session):
PGPLOT_DIR=`brew --prefix pgplot`/share
if [ -e $PGPLOT_DIR ]; then
export PGPLOT_DIR=$PGPLOT_DIR
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$PGPLOT_DIR
fi