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(1) What should we call the axes of a 2-dimensional graph (in general)?
horizontal and vertical
x and y
independent and dependent
I am amazed how many students don't know horizontal and vertical,
but
probably they are more familiar with that than with independent and
dependent.
x and y are usually understood, and that is usually what spreadsheets call
them, but it seems odd to call them x and y when we are not plotting y as a
function of x, but perhaps plotting current as a function of voltage.
If we are plotting current as a function of voltage, is it just best to get
over my hangup and tell the students that voltage is on the x-axis and
current is on the y-axis?
(2) If I tell students to "plot current versus voltage," or my preferred way
is to say "plot current as a function of voltage," many will ask which do I
mean is the x-axis, etc. Those who don't ask seem to have a 50/50 chance of
doing it backwards.
Am I old fashioned?
If I use the phrase "plot current as a function of
voltage" would most (all?) practicing physicists understand I am askling for
current on y and voltage on x?
If so, why aren't students learning this?
If not, what terminology should I be using if I want to use what's being
practiced?
(3) What alternative words do we have for a 3-D coordinate system? For a
standard right-hand system I generally say the x-axis runs left to right
(right positive), the y-axis runs backward to forward (forward positive),
and the z-axis runs bottom to top (top positive).
I know axes can point anyway you want them to point, but do most people
generally visualize it as I said? In textbooks we often see x to the right,
y pointing up, and z pointing backwards. To me, that does not fit with
other practical things such as numerically-controlled milling machines, etc.
Bottom line... if there is some standard language that is different than
what I visualize, I have missed it, and so have many years of students. If
there isn't any standard language, or if the standard is not being taught,
no wonder students are confused.