| | Graphing Parametric Equations, Functions, Curves and Surfaces with DPGraph |
 | | In addition to its implicit and vector graphing capabilities, DPGraph lets you create parametric graphs ranging from simple 2D parametric curves through 5D parametric surfaces (three spacial dimensions, plus time and color). |
 | | To ensure that the top and bottom of the tube don't get cut off by the box, you can change the minimum and maximum Z values of the box to -3.5 and 3.5 from their default values of -3 and 3: |
 | | The basic idea is to start with a torus, for example one with a major radius of 2 and a minor radius of 0.9: |
| www.dpgraph.com /parametric-equations.html (217 words) |