Egad! I had no idea of how confused my students must have been as I blithely
discussed that the independent variable should be on the x or horizontal
axis and the dependent on the y or vertical axis. How else can you plot a
function? I am sure I was understood. Then again, my teen aged children
understood what I meant by being home by 11 PM. ;-)
My students taught me how to distinguish ordinate from absissa. They learned
from a math teacher. When you say absissa, your mouth stretches horizontally
(assuming a normal sitting or standing position) with the ..iss.. sound and
for ordinate the mouth goes vertical when saying or....Now you know, too.
Ken Fox
(I am not convinced that the H-R diagram is designed to be a functional plot
and thus does not follow any of the rules we have been trying to agree
upon.)