What is a justified way to visualize one-dimensional geometrical configuration of dust molecular clouds?

In continuation, it is well known that a spherical (3-D) problem (with total degree of freedom # 3) could be reduced into a radial (1-D) problem (with total degree of freedom # 1) at the backdrop of spherically symmetric geometry. In both the cases (3-D + 1-D), the radial coordinate, r, can be well visualized in a sphere.

The same problem for analytic simplicity can also be worked out in a planar cartesian geometry (1-D). In this case, what does the cartesian position coordinate, x, represent? Is it possible to draw a crystal clear pictorial visualization of the latter in reference with the former under the condition that r=x if and only if (1/r)~0?