MATLAB Function Reference

Line Properties - Line properties

Modifying Properties

You can set and query graphics object properties in two ways:

• The The Property Editor is an interactive tool that enables you to see and change object property values.

• The set and get commands enable you to set and query the values of properties.

To change the default values of properties, see Setting Default Property Values.

See Core Graphics Objects for general information about this type of object.

Line Property Descriptions

This section lists property names along with the type of values each accepts. Curly braces { } enclose default values.

Annotation

hg.Annotation object Read Only

Control the display of line objects in legends. The Annotation property enables you to specify whether this line object is represented in a figure legend.

Querying the Annotation property returns the handle of an hg.Annotation object. The hg.Annotation object has a property called LegendInformation, which contains an hg.LegendEntry object.

Once you have obtained the hg.LegendEntry object, you can set its IconDisplayStyle property to control whether the line object is displayed in a figure legend:

IconDisplayStyle Value	Purpose
on	Represent this line object in a legend (default)
off	Do not include this line object in a legend
children	Same as on because line objects do not have children

Setting the IconDisplayStyle property

These commands set the IconDisplayStyle of a graphics object with handle hobj to off:

hAnnotation = get(hobj,'Annotation');
hLegendEntry = get(hAnnotation','LegendInformation');
set(hLegendEntry,'IconDisplayStyle','off')

Using the IconDisplayStyle property

See Controlling Legends for more information and examples.

BeingDeleted

on | {off} Read Only

This object is being deleted. The BeingDeleted property provides a mechanism that you can use to determine if objects are in the process of being deleted. MATLAB sets the BeingDeleted property to on when the object's delete function callback is called (see the DeleteFcn property). It remains set to on while the delete function executes, after which the object no longer exists.

For example, an object's delete function might call other functions that act on a number of different objects. These functions may not need to perform actions on objects that are going to be deleted and, therefore, can check the object's BeingDeleted property before acting.

BusyAction

cancel | {queue}

Callback routine interruption. The BusyAction property enables you to control how MATLAB handles events that potentially interrupt executing callback routines. If there is a callback routine executing, callback routines invoked subsequently always attempt to interrupt it. If the Interruptible property of the object whose callback is executing is set to on (the default), then interruption occurs at the next point where the event queue is processed. If the Interruptible property is off, the BusyAction property (of the object owning the executing callback) determines how MATLAB handles the event. The choices are

• cancel — Discard the event that attempted to execute a second callback routine.

• queue — Queue the event that attempted to execute a second callback routine until the current callback finishes.

ButtonDownFcn

functional handle, cell array containing function handle and additional arguments, or string (not recommended)

Button press callback function. A callback function that executes whenever you press a mouse button while the pointer is over the line object.

See the figure's SelectionType property to determine if modifier keys were also pressed.

Set this property to a function handle that references the callback. The function must define at least two input arguments (handle of line associated with the button down event and an event structure, which is empty for this property)

The following example shows how to access the callback object's handle as well as the handle of the figure that contains the object from the callback function.

function button_down(src,evnt)
% src - the object that is the source of the event
% evnt - empty for this property
   sel_typ = get(gcbf,'SelectionType')
   switch sel_typ 
      case 'normal'
         disp('User clicked left-mouse button')
         set(src,'Selected','on')
      case 'extend'
         disp('User did a shift-click')
         set(src,'Selected','on')
      case 'alt'
         disp('User did a control-click')
         set(src,'Selected','on')
         set(src,'SelectionHighlight','off')
   end
end

Suppose h is the handle of a line object and that the button_down function is on your MATLAB path. The following statement assigns the function above to the ButtonDownFcn:

set(h,'ButtonDownFcn',@button_down)

See Function Handle Callbacks for information on how to use function handles to define the callback function.

Children

vector of handles

The empty matrix; line objects have no children.

Clipping

{on} | off

Clipping mode. MATLAB clips lines to the axes plot box by default. If you set Clipping to off, lines are displayed outside the axes plot box. This can occur if you create a line, set hold to on, freeze axis scaling (set axis to manual), and then create a longer line.

Color

ColorSpec

Line color. A three-element RGB vector or one of the MATLAB predefined names, specifying the line color. See the ColorSpec reference page for more information on specifying color.

CreateFcn

functional handle, cell array containing function handle and additional arguments, or string (not recommended)

Callback function executed during object creation. A callback function that executes when MATLAB creates a line object. You must define this property as a default value for lines or in a call to the line function to create a new line object. For example, the statement

set(0,'DefaultLineCreateFcn',@line_create)

defines a default value for the line CreateFcn property on the root level that sets the axes LineStyleOrder whenever you create a line object. The callback function must be on your MATLAB path when you execute the above statement.

function line_create(src,evnt)
% src - the object that is the source of the event 
% evnt - empty for this property
	axh = get(src,'Parent'); 
	set(axh,'LineStyleOrder','-.|--')
end

MATLAB executes this function after setting all line properties. Setting this property on an existing line object has no effect. The function must define at least two input arguments (handle of line object created and an event structure, which is empty for this property).

The handle of the object whose CreateFcn is being executed is passed by MATLAB as the first argument to the callback function and is also accessible through the root CallbackObject property, which you can query using gcbo.

See Function Handle Callbacks for information on how to use function handles to define the callback function.

DeleteFcn

functional handle, cell array containing function handle and additional arguments, or string (not recommended)

Delete line callback function. A callback function that executes when you delete the line object (e.g., when you issue a delete command or clear the axes cla or figure clf). For example, the following function displays object property data before the object is deleted.

function delete_fcn(src,evnt)
% src - the object that is the source of the event 
% evnt - empty for this property
   obj_tp = get(src,'Type');
   disp([obj_tp, ' object deleted'])
   disp('Its user data is:')
   disp(get(src,'UserData'))
end

MATLAB executes the function before deleting the object's properties so these values are available to the callback function. The function must define at least two input arguments (handle of line object being deleted and an event structure, which is empty for this property)

The handle of the object whose DeleteFcn is being executed is passed by MATLAB as the first argument to the callback function and is also accessible through the root CallbackObject property, which you can query using gcbo.

See Function Handle Callbacks for information on how to use function handles to define the callback function.

DisplayName

string (default is empty string)

String used by legend for this line object. The legend function uses the string defined by the DisplayName property to label this line object in the legend.

• If you specify string arguments with the legend function, DisplayName is set to this line object's corresponding string and that string is used for the legend.

• If DisplayName is empty, legend creates a string of the form, ['data' n], where n is the number assigned to the object based on its location in the list of legend entries. However, legend does not set DisplayName to this string.

• If you edit the string directly in an existing legend, DisplayName is set to the edited string.

• If you specify a string for the DisplayName property and create the legend using the figure toolbar, then MATLAB uses the string defined by DisplayName.

• To add programmatically a legend that uses the DisplayName string, call legend with the toggle or show option.

See Controlling Legends for more examples.

The following code shows how to use the DisplayName property from the command line or in an M-file.

t = 0:.1:2*pi;
a(:,1)=sin(t); a(:,2)=cos(t);
h = plot(a);
set(h,{'DisplayName'},{'Sine','Cosine'}')
legend show

EraseMode

{normal} | none | xor | background

Erase mode. This property controls the technique MATLAB uses to draw and erase line objects. Alternative erase modes are useful for creating animated sequences, where control of the way individual objects are redrawn is necessary to improve performance and obtain the desired effect.

• normal (the default) — Redraw the affected region of the display, performing the three-dimensional analysis necessary to ensure that all objects are rendered correctly. This mode produces the most accurate picture, but is the slowest. The other modes are faster, but do not perform a complete redraw and are therefore less accurate.

• none — Do not erase the line when it is moved or destroyed. While the object is still visible on the screen after erasing with EraseMode none, you cannot print it, because MATLAB stores no information about its former location.

• xor — Draw and erase the line by performing an exclusive OR (XOR) with the color of the screen beneath it. This mode does not damage the color of the objects beneath the line. However, the line's color depends on the color of whatever is beneath it on the display.

• background — Erase the line by drawing it in the axes background Color, or the figure background Color if the axes Color is set to none. This damages objects that are behind the erased line, but lines are always properly colored.

Printing with Nonnormal Erase Modes

MATLAB always prints figures as if the EraseMode of all objects is normal. This means graphics objects created with EraseMode set to none, xor, or background can look different on screen than on paper. On screen, MATLAB may mathematically combine layers of colors (e.g., performing an XOR on a pixel color with that of the pixel behind it) and ignore three-dimensional sorting to obtain greater rendering speed. However, these techniques are not applied to the printed output.

You can use the MATLAB getframe command or other screen capture application to create an image of a figure containing nonnormal mode objects.

HitTest

{on} | off

Selectable by mouse click. HitTest determines if the line can become the current object (as returned by the gco command and the figure CurrentObject property) as a result of a mouse click on the line. If HitTest is off, clicking the line selects the object below it (which may be the axes containing it).

HandleVisibility

{on} | callback | off

Control access to object's handle by command-line users and GUIs. This property determines when an object's handle is visible in its parent's list of children. HandleVisibility is useful for preventing command-line users from accidentally drawing into or deleting a figure that contains only user interface devices (such as a dialog box).

Handles are always visible when HandleVisibility is on.

Setting HandleVisibility to callback causes handles to be visible from within callback routines or functions invoked by callback routines, but not from within functions invoked from the command line. This provides a means to protect GUIs from command-line users, while allowing callback routines to have complete access to object handles.

Setting HandleVisibility to off makes handles invisible at all times. This may be necessary when a callback routine invokes a function that might potentially damage the GUI (such as evaluating a user-typed string), and so temporarily hides its own handles during the execution of that function.

When a handle is not visible in its parent's list of children, it cannot be returned by functions that obtain handles by searching the object hierarchy or querying handle properties. This includes get, findobj, gca, gcf, gco, newplot, cla, clf, and close.

When a handle's visibility is restricted using callback or off, the object's handle does not appear in its parent's Children property, figures do not appear in the root's CurrentFigure property, objects do not appear in the root's CallbackObject property or in the figure's CurrentObject property, and axes do not appear in their parent's CurrentAxes property.

You can set the root ShowHiddenHandles property to on to make all handles visible regardless of their HandleVisibility settings (this does not affect the values of the HandleVisibility properties).

Handles that are hidden are still valid. If you know an object's handle, you can set and get its properties, and pass it to any function that operates on handles.

Interruptible

{on} | off

Callback routine interruption mode. The Interruptible property controls whether a line callback routine can be interrupted by subsequently invoked callback routines. Only callback routines defined for the ButtonDownFcn are affected by the Interruptible property. MATLAB checks for events that can interrupt a callback routine only when it encounters a drawnow, figure, getframe, or pause command in the routine.

LineStyle

{-} | -- | : | -. | none

Line style. This property specifies the line style. Available line styles are shown in the table.

Symbol	Line Style
'–'	Solid line (default)
'--'	Dashed line
':'	Dotted line
'–.'	Dash-dot line
'none'	No line

You can use LineStyle none when you want to place a marker at each point but do not want the points connected with a line (see the Marker property).

LineWidth

scalar

The width of the line object. Specify this value in points (1 point = ¹/₇₂ inch). The default LineWidth is 0.5 points.

Marker

character (see table)

Marker symbol. The Marker property specifies marks that display at data points. You can set values for the Marker property independently from the LineStyle property. Supported markers include those shown in the table.

Marker Specifier	Description
'+'	Plus sign
'o'	Circle
'*'	Asterisk
'.'	Point
'x'	Cross
'square' or 's'	Square
'diamond' or 'd'	Diamond
'^'	Upward-pointing triangle
'v'	Downward-pointing triangle
'>'	Right-pointing triangle
'<'	Left-pointing triangle
'pentagram' or 'p'	Five-pointed star (pentagram)
'hexagram' or 'h'	Six-pointed star (hexagram)
'none'	No marker (default)

MarkerEdgeColor

ColorSpec | none | {auto}

Marker edge color. The color of the marker or the edge color for filled markers (circle, square, diamond, pentagram, hexagram, and the four triangles). ColorSpec defines the color to use. none specifies no color, which makes nonfilled markers invisible. auto sets MarkerEdgeColor to the same color as the line's Color property.

MarkerFaceColor

ColorSpec | {none} | auto

Marker face color. The fill color for markers that are closed shapes (circle, square, diamond, pentagram, hexagram, and the four triangles). ColorSpec defines the color to use. none makes the interior of the marker transparent, allowing the background to show through. auto sets the fill color to the axes color, or the figure color, if the axes Color property is set to none (which is the factory default for axes).

MarkerSize

size in points

Marker size. A scalar specifying the size of the marker, in points. The default value for MarkerSize is six points (1 point = 1/72 inch). Note that MATLAB draws the point marker (specified by the '.' symbol) at one-third the specified size.

Parent

handle of axes, hggroup, or hgtransform

Parent of line object. This property contains the handle of the line object's parent. The parent of a line object is the axes that contains it. You can reparent line objects to other axes, hggroup, or hgtransform objects.

See Objects That Can Contain Other Objects for more information on parenting graphics objects.

Selected

on | off

Is object selected? When this property is on. MATLAB displays selection handles if the SelectionHighlight property is also on. You can, for example, define the ButtonDownFcn to set this property, allowing users to select the object with the mouse.

SelectionHighlight

{on} | off

Objects are highlighted when selected. When the Selected property is on, MATLAB indicates the selected state by drawing handles at each vertex. When SelectionHighlight is off, MATLAB does not draw the handles.

Tag

string

User-specified object label. The Tag property provides a means to identify graphics objects with a user-specified label. This is particularly useful when you are constructing interactive graphics programs that would otherwise need to define object handles as global variables or pass them as arguments between callback routines. You can define Tag as any string.

Type

string (read only)

Class of graphics object. For line objects, Type is always the string 'line'.

UIContextMenu

handle of a uicontextmenu object

Associate a context menu with the line. Assign this property the handle of a uicontextmenu object created in the same figure as the line. Use the uicontextmenu function to create the context menu. MATLAB displays the context menu whenever you right-click over the line.

UserData

matrix

User-specified data. Any data you want to associate with the line object. MATLAB does not use this data, but you can access it using the set and get commands.

Visible

{on} | off

Line visibility. By default, all lines are visible. When set to off, the line is not visible, but still exists, and you can get and set its properties.

XData

vector of coordinates

X-coordinates. A vector of x-coordinates defining the line. YData and ZData must be the same length and have the same number of rows. (See Examples.)

YData

vector of coordinates

Y-coordinates. A vector of y-coordinates defining the line. XData and ZData must be the same length and have the same number of rows.

ZData

vector of coordinates

Z-coordinates. A vector of z-coordinates defining the line. XData and YData must have the same number of rows.

line

Lineseries Properties