Slide 14 of 42
This curve is a three-dimensional plot of data value f and the first
derivative f' as a function of position. If you project the curve
downward, you get back the plot of f(x), which we saw before here. If
you project the curve this way, you get back the plot of f'(x), which
we also saw before. But you can also project the curve this way,
along the position axis, to get this new curve, which is a parametric
plot of f' versus f, as a function of position x.
