xline — Draw vertical reference lines on current or specified axes with MATLAB-compatible styling forms.
xline adds one or more vertical reference lines with optional labels, line specs, and name-value styling, following MATLAB-compatible plotting behavior.
Syntax
h = xline(x)
h = xline(x, styleOrLabel)
h = xline(x, LineSpec, label)
h = xline(x, Name, Value, ...)Inputs
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
x | NumericArray | Yes | — | X-coordinate scalar or numeric vector of vertical line positions. |
style_or_label | Any | No | — | LineSpec token (for example '--r') or label text. |
linespec | StyleSpec | Yes | — | Line style token (for example '--r'). |
label | StringScalar | Yes | — | Reference line label text. |
props | Any | Variadic | — | Style arguments and Name/Value pairs (Color, LineWidth, LineStyle, LabelOrientation, Visible). |
Returns
| Name | Type | Description |
|---|---|---|
h | NumericArray | Reference line handle scalar or row vector when multiple coordinates are provided. |
Errors
| Identifier | When | Message |
|---|---|---|
RunMat:xline:InvalidArgument | Coordinate input, style arguments, or Name/Value pairs are invalid. | xline: invalid argument |
RunMat:xline:Internal | Internal plotting state update fails. | xline: internal operation failed |
How xline works
xline(x)adds a vertical reference line at each coordinate inx.- Reference lines append to the current axes without replacing existing plot content.
- Line spans follow the active axes limits, including later
xlimandylimchanges. - The returned handle supports
getandsetforValue,Color,LineWidth,LineStyle,Label,LabelOrientation,DisplayName, andVisible.
Examples
Add a dashed threshold line
plot(1:10, rand(1, 10));
xline(5, '--r', 'Threshold');Expected output:
% Adds a red dashed vertical reference line at x = 5Add multiple reference lines
plot(1:10, rand(1, 10));
xline([2 5 8], ':');Expected output:
% Adds three dotted vertical reference linesUsing xline with coding agents
Open a RunMat example with live inputs, then ask the agent to explain how xline changes the result.
Run a small xline example, explain the result, then change one input and compare the output.
Related Plotting functions
About RunMat
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