figure properties

Description

The figure entity is the top level of the graphics entities hierarchy. This entity contain a number of properties designed to control many aspects of displaying Scilab graphics objects. These properties fall into two categories. Properties that contain information about figure itself and others related to set default values for the children creation.

Figure properties:

children:

This handles represent the vector of the figure's children . Note that all figure children are of type "Axes". Also keep in mind that, when creating a figure entity (using scf command), an Axes entity is simultaneously built too.

figure_style:

The value of this field defines the figure style. Since Scilab 5.0, old graphic mode has been disable. This property will be removed in Scilab 5.4 family.

figure_position:

This field contains the position in pixel of the graphic window on the screen. This is a vector [x,y] defining the position of the upper-left corner of the window. The position [0,0] is the upper-left corner of the screen.

The initial position of graphic windows is taken from the default figure entity (see gdf). The only exception is when default figure figure_position value is [-1,-1]. In this case, the initial position of graphic windows is automatically set by the windowing system.

figure_size:

This property controls the size in pixel of the screen's graphics window. The size is the vector [width,height].

axes_size:

Used to Specifies the size in pixel of the virtual graphics window. The size is the vector [width,height]. The virtual graphic window should be bigger than the part really visible on the screen. This property could not be modified if the figure is docked with other elements.

auto_resize:

This property determines if graphics window is resized. If the value is "on" then the axes_size property is equaled to the figure_size and the axes children are zoomed accordingly. If the value is "off" that indicate that axes_size cannot be resized when figure_size is changed.

viewport:

Postion of the visible part of graphics in the panner.

figure_name:

This field contains the name of the figure. This name is a character string displayed at the top of the graphics_window. The name can contain a single substring %d which will be replaced by the figure_id. No other instance of the % character is allowed inside the name.

figure_id:

This field contains the identifier of the figure. This is an integer number which is set at figure creation and cannot be changed after.

info_message:

This character string set the text displayed in the info bar of the graphic window.

color_map:

Property which defines the colormap used by this figure. The colormap is a m by 3 matrix. m is the number of colors. Color number i is given as a 3-uple R, G, B corresponding respectively to red, green and blue intensity between 0 and 1.

pixmap:

This property controls the pixmap status of a Graphic Window. If this property value is "off" the graphics are directly displayed on the screen. If it is "on" the graphics are done on a pixmap and are sent to the graphics window with the command show_pixmap().

pixel_drawing_mode:

This field specifies the bitwise operation used for pixel rendering. The default mode is copy. For more details see the pixel drawing mode reference page.

anti_aliasing:

This property controls the anti-aliasing level used to improve graphic quality. If the property is set to "off", anti-aliasing is disable. To enable anti-aliasing the property must set to either "2x", "4x", "8x" or "16x". In this case, it stands for the anti-aliasing level. For example, "16x" is a higher quality level than "2x". Specifying a higher anti-aliasing level improves image quality but also decreases graphic performances.

immediate_drawing:

This property controls the figure display. Its value can be "on" (default mode) or "off". It is used to delay a huge succession of graphics commands (implying several drawings or redrawings). Note that, when using drawlater or drawnow commands, it affects the property value of the current figure (which is respectively turned to 'off' or 'on').

background:

This property controls the figure window background color. It takes as value an index relative to the current colormap.

event_handler

A character string. The name of the Scilab function which is intended to handle the events. Not that setting an empty string will disable the event handler. For more information about event handler functions see the event handler functions help.

event_handler_enable

Enable or disable the event handler. Its value must be either "on" or "off".

user_data:

This field can be use to store any scilab variable in the figure data structure, and to retreive it.

tag:

This field can be use to store a character string generally used to identify the control. It allows to give it a "name". Mainly used in conjontion with findobj().

resizefcn:

This field can be used to store the name of a Scilab function or a Scilab expression as a character string. This character string will be evaluated whenever the user resizes the figure and when the figure is created.

closerequestfcn:

This field can be used to store the name of a Scilab function or a Scilab expression as a character string. This character string will be evaluated whenever the user tries to close the figure using the top-right cross.

When this property is set, the "figure closed" event (-1000) will no more be trapped by the event handler function.

Children's default values:

visible:

This field ules if the contents of the figure as to be redrawn. Its value should be "on" or "off".

rotation_style:

This field is related to the "3D Rot" button. It takes unary as value (default) in the aim to rotate only selected 3D plot. In the other case its value can be multiple : all 3D plots are rotated.

Note on default values :

All these listed properties and fields inherit from default values stored in a figure model. These default values can be seen and changed. To do so, use the get("default_figure") command : it returns a graphic handle on the figure model. Note that no graphic window is created by this command. The next created figures will inherit from this model (see example 2 below).

Examples

lines(0) // disables vertical paging 

//Example 1
f=get("current_figure") //get the handle of the current figure : 
                        //if none exists, create a figure and return the corresponding handle
f.figure_position
f.figure_size=[200,200]
f.background=2
f.children  // man can see that an Axes entity already exists
delete(f);
f=gcf(); // macro shortcut <=> f=get("current_figure")
f.pixmap = "on" // set pixmap status to on
plot2d() // nothing happens on the screen...
show_pixmap() // ...display the pixmap on screen

//Example 2 : default_figure settings
df=get("default_figure") // get the default values (shortcut is gdf() )
// Let's change the defaults...
df.color_map=hotcolormap(128)
df.background= 110 // set background toa kind of yellow (Note that we
                   // are using a color index inside the color_map previously redefined)
scf(122); // creates new figure number 122 with the new default
plot2d()
scf(214);
t=-%pi:0.3:%pi;
plot3d(t,t,sin(t)'*cos(t),35,45,'X@Y@Z',[15,2,4]);

See Also

• lines — rows and columns used for display
• set — set a property value of a graphic entity object or of a User Interface object.
• get — Retrieve a property value from a graphics entity or an User Interface object.
• scf — set the current graphic figure (window)
• gcf — Return handle of current graphic window.
• gdf — Return handle of default figure.
• gca — Return handle of current axes.
• gda — Return handle of default axes.
• axes_properties — description of the axes entity properties
• show_pixmap — send the pixmap buffer to the screen This function is obsolete.
• clear_pixmap — erase the pixmap buffer This function is obsolete.
• hotcolormap — red to yellow colormap
• event handler functions — Prototype of functions which may be used as event handler.

History