Managing Default Properties (GNU Octave (version 9.1.0))

#### 15.3.5 Managing Default Properties ¶

Object properties have two classes of default values, factory defaults (the initial values) and user-defined defaults, which may override the factory defaults.

Although default values may be set for any object, they are set in parent objects and apply to child objects, of the specified object type. For example, setting the default `color` property of `line` objects to `"green"`, for the `root` object, will result in all `line` objects inheriting the `color` `"green"` as the default value.

    set (groot, "defaultlinecolor", "green");

sets the default line color for all objects. The rule for constructing the property name to set a default value is

    default + object-type + property-name

This rule can lead to some strange looking names, for example `defaultlinelinewidth"` specifies the default `linewidth` property for `line` objects.

The example above used the root object so the default property value will apply to all line objects. However, default values are hierarchical, so defaults set in a figure objects override those set in the root object. Likewise, defaults set in an axes object override those set in figure or root objects. For example,

    subplot (2, 1, 1);
    set (groot, "defaultlinecolor", "red");
    set (1, "defaultlinecolor", "green");
    set (gca (), "defaultlinecolor", "blue");
    line (1:10, rand (1, 10));
    subplot (2, 1, 2);
    line (1:10, rand (1, 10));
    figure (2)
    line (1:10, rand (1, 10));

produces two figures. The line in first subplot window of the first figure is blue because it inherits its color from its parent axes object. The line in the second subplot window of the first figure is green because it inherits its color from its parent figure object. The line in the second figure window is red because it inherits its color from the global root object.

To remove a user-defined default setting, set the default property to the value `"remove"`. For example,

    set (gca (), "defaultlinecolor", "remove");

removes the user-defined default line color setting from the current axes object. To quickly remove all user-defined defaults use the `reset` function.

By default, high level plotting functions such as `plot` reset and redefine axes properties independently from the defaults. An example of such property is the axes `box` property: it is set `on` by high level 2-D graphics functions regardless of the property `"defaultaxesbox"`. Use the `hold` function to prevent this behavior:

    set (groot, "defaultaxesbox", "off");
    subplot (2, 1, 1);
    plot (1:10)
    title ("Box is on anyway")
    subplot (2, 1, 2);
    hold on
    plot (1:10)
    title ("Box is off")

: reset `(h)` ¶

  Reset the properties of the graphic object h to their default values.

  For figures, the properties `"position"`, `"units"`, `"windowstyle"`, and `"paperunits"` are not affected. For axes, the properties `"position"` and `"units"` are not affected.

  The input h may also be a vector of graphic handles in which case each individual object will be reset.

  See also: cla, clf, newplot.

Getting the `"default"` property of an object returns a list of user-defined defaults set for the object. For example,

    get (gca (), "default");

returns a list of user-defined default values for the current axes object.

Factory default values are stored in the root object. The command

    get (groot, "factory");

returns a list of factory defaults.