Drag on the graph to rotate it.
The definitions of x(u,v), y(u,v),
and z(u,v) can use: the variables u and v; the operators +, −, *,
and /; the functions sin(x), cos(x), atan(x),
abs(x), exp(x), log(x), and pow(x,y); and
the constant pi. Note that there is no exponential operator, but pow(x,y)
does exponentiation. Angles are measured in radians. The scale determines the range of
coordinates that are in view. Coordinates in the range −scale to scale
should be visible. If axes are drawn, they extend from −scale to scale along
each coordinate axis. The y-axis (green) points upward, the z-axis (blue) points out of the screen,
and the x-axis (red) points to the right.