Allowed options:
max => maximal face color (default: red)
min => minimal face color (default: yellow)

The methods described below can be used to add more details to drawings created by the following visualization methods:

Polytope::VISUAL_GRAPH TightSpan::VISUAL_EDGE_COLORED_BOUNDED_GRAPH TightSpan::VISUAL_BOUNDED_GRAPH
VERTEX_COLORS
Illustrate the behavior of a linear objective function on the polytope. Color the nodes according to the value the objective function takes on the vertices (VERTEX_COLORS)
The spring embedder applies an additional force, which tries to arrange the nodes in the z-axis direction corresponding to the objective function values.
MIN_MAX_FACE (options)
Illustrate the behavior of a linear objective function on the polytope. The vertices belonging to MINIMAL_FACE and MAXIMAL_FACE are drawn in distinct colors
The spring embedder applies an additional force, which tries to arrange the nodes in the z-axis direction corresponding to the objective function values.
DIRECTED_GRAPH
Show the growth direction of a linear objective function via arrowed edges.

Each auxiliary method always returns the visual object it was called with ($this), which makes it easy to build longer method chains of the kind: VISUAL->DIRECTED_GRAPH->VERTEX_COLORS .