Constant line appearance and behavior (2024)

Location of the constant line on the x- or y-axis, specified as a scalar. You can specify the value as a numeric, categorical, datetime, or duration value.

Example

Create a constant line at x = 5.5. Then change the value to 7.

xl = xline(5.5);xl.Value = 7;

Since R2024a

Layer position, specified as "bottom" or "top". A value of "bottom" displays the ConstantLine object under other items in the axes, such as lines or markers. A value of "top" displays the ConstantLine object on top of other items.

Passing a ConstantLine object to the uistack function has no effect on its stacking order, nor does reordering the Children property of the axes.

Line label, specified as a character vector, cell array of character vectors, string array, or numeric array. To create a multiline label, use a string array or a cell array of character vectors.

Example: "cutoff frequency"

Example: ["One row of text","A second row of text"]

Example: {'One row of text','A second row of text'}

To include special characters, such as superscripts, subscripts, Greek letters, or mathematical symbols, use TeX markup. For a list of supported markup, see the Interpreter property.

Horizontal alignment of the label with respect to the line, specified as one of the options in the table.

Vertical alignment of the label with respect to the line, specified as one of the options in the table.

Label orientation, specified as 'aligned' or 'horizontal'. Examples are shown in the table.

Line color, specified as an RGB triplet, a hexadecimal color code, a color name, or a short name.

For a custom color, specify an RGB triplet or a hexadecimal color code.

Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB uses in many types of plots.

Example: 'g'

Example: [0.6 0.2 0.5]

Example: '#D2F9A7'

Series index, specified as a positive whole number or "none". This property is useful for reassigning the colors and line styles of ConstantLine objects so that they match other objects.

When the SeriesIndex property is a number, MATLAB uses the number to calculate indices for assigning colors and line styles when you call the xline or yline functions. The indices refer to the rows of the arrays stored in the ColorOrder and LineStyleOrder properties of the axes. Any objects in the axes that have the same SeriesIndex number will have the same color (and line style, if applicable).

A SeriesIndex value of "none" corresponds to a solid line with a neutral color that does not participate in the indexing scheme.

How Manually Setting Colors, Line Styles, or Markers Overrides SeriesIndex Behavior

To manually control the color and line style, set the Color and LineStyle properties of the ConstantLine object.

When you manually set these properties of an object, MATLAB disables automatic color and line style selection for that object and allows your selection to persist, regardless of the value of the SeriesIndex property. The ColorMode and LineStyleMode properties indicate whether the colors and line styles have been set manually (by you) or automatically. For each of these mode properties, a value of "manual" indicates manual selection, and "auto" indicates automatic selection.

To enable automatic selection again, set the ColorMode, LineStyleMode, or both properties to "auto", and set the SeriesIndex property to a positive whole number.

In some cases, MATLAB sets the SeriesIndex property to 0, which also disables automatic color selection.

This property is read-only.

Type of graphics object, returned as 'constantline'. Use this property to find all objects of a given type within a plotting hierarchy, for example, searching for the type using findobj.