Installing the Graphviz in macOS

For macOS

#Download the source tar file from here
https://www.macports.org/install.php#installing 

file name would be [MacPorts-2.4.1.tar.bz2]

“cd” into the directory where you downloaded the package and run “tar xjvf MacPorts-2.4.1.tar.bz2”  
Build and install the recently unpacked sources:
cd MacPorts-2.4.1
./configure && make && sudo make install

In the process it will ask you for root pass word

after installing 
 export the installation directory to the path using the following command in terminal
 
 export PATH=/opt/local/bin:/opt/local/sbin:$PATH


Then From http://www.graphviz.org/Download_macos.php
Follwo the isntruction for the installation