Post date: Apr 1, 2017 12:17:16 AM
Different tools exist to model what an antenna might do:
http://www.w7ay.net/site/Applications/cocoaNEC/
https://radio.linux.org.au/?sectpat=antenna
https://github.com/wsnook/nec2-toys
http://www.nec2.org/
http://fermi.la.asu.edu/w9cf/yagipub/index.html