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VectorScale

Status: Experimental

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

Description

VectorScale

VectorPlot option: controls arrow length. Automatic (default): all arrows drawn at equal length (direction only) None: length proportional to field magnitude real f: arrow length = f × grid spacing

Examples (3)

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

Applications (3)

An inert, Protected option keyword

In[1]:= Attributes[VectorScale]
Out[1]= {Protected}

No value of its own: evaluates to itself

In[2]:= VectorScale
Out[2]= VectorScale

Read inside a VectorPlot

In[3]:= Head[VectorPlot[{1, x}, {x, -1, 1}, {y, -1, 1}, VectorScale -> 0.5]]
Out[3]= Graphics

Implementation notes

Definition. VectorScale is an option symbol for VectorPlot that controls how arrow length encodes field magnitude. It has no builtin and no value of its own — it is an inert keyword (Protected) read out of VectorPlot's option sequence.

Representation. A bare EXPR_SYMBOL (interned SYM_VectorScale). VectorPlot's option parser (src/graphics/vectorplot.c) evaluates the right-hand side of a VectorScale -> v rule and sets an internal scale_mode: Automatic (the default) → VS_AUTOMATIC, all arrows drawn at equal display length so only direction is shown; None → VS_NONE, length proportional to field magnitude; a positive real f → VS_FRACTION with arrow length = f × grid spacing. Any other value falls back to Automatic.

Usage & limits. Protected. It carries meaning only inside a VectorPlot call; on its own it just evaluates to itself. It has no entry in Options[VectorPlot]'s default list — it is read directly from the given option sequence — so SetOptions on it has no effect. Companion VectorPlot options are VectorPoints (seed-grid density) and VectorStyle (global style directives).

Attributes: Protected.

References

Notes & additional examples

Notes

VectorScale is a VectorPlot option controlling how arrow length encodes the field. Automatic (the default) draws every arrow at equal length, showing direction only; None makes length proportional to the field magnitude; a positive real f sets arrow length to f × the grid spacing.

It is an inert, Protected keyword with no value of its own, read straight from the VectorPlot option sequence (it is not in Options[VectorPlot]'s default list, so SetOptions on it has no effect). The companion keywords are VectorPoints (seed-grid density) and VectorStyle (global style directives).