SmResCircle

Draws a constant-resistance circle. All points on the circle share the same normalised resistance r, with reactance x varying from −∞ to +∞.

Demo

:res 0.50

Enable :crop

<SmResCircle :res="0.50" />

Usage

<SmithChart>
  <!-- Full circle -->
  <SmResCircle :res="1" fill="rgba(0,0,255,0.2)" />

  <!-- Cropped: only show the arc outside the reactance circle x=2 -->
  <SmResCircle
    :res="0.5"
    :crop="2"
    fill="none"
    stroke="#e53e3e"
    stroke-width="3"
  />
</SmithChart>

Props

Prop	Type	Default	Description
res	Number | String	—	Normalised resistance value for the circle.
crop	Number | String	''	When set, masks away the portion of the circle that falls inside the constant-reactance arc of magnitude crop. Use this to draw only the segment of the circle relevant to a matching path.

SVG presentation attributes (fill, stroke, stroke-width, opacity, etc.) pass through to the underlying <circle>.

How it works

A constant-resistance circle for value r has:

• Centre: (r / (r + 1), 0) in normalised coordinates
• Radius: 1 / (r + 1) in normalised coordinates

The crop prop uses an SVG mask generated by the matching <SmReactArc> to clip away the unwanted portion.

Common values

res	Position
0	The outermost circle (short circuit locus)
0.5	Left half of the chart
1	Circle passing through the chart centre
2, 5, 10	Smaller circles near the right edge