@rproffitt: Nic tip thanks.
@ddanbe. I am at times old school. This is one of those times it shows. Such a plotting system for me has always been used in some automated reporting system. So the "web distributed" or cloud based systems are rarely used by folk I know. And for now Gnuplot doesn't want me to sign up.
Hope this explains why I offered up Ol' Gnuplot.