ContourStyle

Status: Experimental

present and registered, but lightly documented and not yet covered by dedicated tests.

Description

ContourStyle

ContourPlot option: style directive(s) for contour lines. A list cycles through the levels; Automatic colours by height; None suppresses lines.

Examples (3)

Every input below was run against the current Mathilda build and its output recorded.

Applications (3)

An inert option keyword: it just names the left of a rule

In[1]:= ContourStyle -> Red
Out[1]= ContourStyle -> RGBColor[1, 0, 0]

Protected, with no value of its own

In[2]:= MemberQ[Attributes[ContourStyle], Protected]
Out[2]= True

Accepted by its owning plot builtin

In[3]:= Head[ContourPlot[x^2 + y^2, {x, -1, 1}, {y, -1, 1}, ContourStyle -> Red]]
Out[3]= Graphics

Implementation notes

Definition. ContourStyle is an inert option keyword for ContourPlot: it gives the style directive(s) for the contour lines; a single directive applies to all levels, a list cycles through them, Automatic colours by height and None suppresses the lines. It has no builtin and no OwnValue — only the Protected attribute bit is set on the symbol in graphics_init.c, where its docstring also lives. It is a name, not a value, and exists so that ContourStyle -> ... can be written in an option list.

Representation. A bare Protected EXPR_SYMBOL. It never evaluates on its own; it is read as the left-hand side of a ContourStyle -> value rule by the owning plot builtin while it assembles the Graphics[...] result, through the shared options plumbing (OptionValue-style lookup). The value on the right is an ordinary expression and is evaluated as usual — so e.g. a colour name on the right reaches the builtin already reduced to its RGBColor[...] literal.

Usage & limits. Meaningful only inside a call to ContourPlot; elsewhere it is an unused symbol. An unrecognised value is handled (or defaulted) by the owning builtin, not by ContourStyle itself, which carries no logic of its own.

Attributes: Protected.

References

• Source: src/graphics/graphics_init.c
• Specification index: Mathilda_spec.md

Notes & additional examples

Notes

ContourStyle is an inert option keyword for ContourPlot — the style directive(s) for contour lines; a list cycles through levels, Automatic colours by height, None suppresses lines. It has no builtin and no own-value; it is Protected and stays symbolic, read only as the left-hand side of a ContourStyle -> value option rule while the owning builtin builds its Graphics[...] result. The right-hand value evaluates normally before the builtin sees it.