matlab.graphics.chartcontainer.ChartContainer.getAxes - Get axes for chart container subclass - MATLAB (original) (raw)

Class: matlab.graphics.chartcontainer.ChartContainer
Namespace: matlab.graphics.chartcontainer

Get axes for chart container subclass

Description

[ax](#mw%5Fa459e303-32a3-4760-aa01-ecd19b5729bb) = getAxes([obj](#mw%5F799f0810-2d11-4c83-8b74-ade1e0ff2049)) returns one or more axes objects for a chart that inherits from thematlab.graphics.chartcontainer.ChartContainer base class.

Input Arguments

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Object of the class that inherits from thematlab.graphics.chartcontainer.ChartContainer base class.

Output Arguments

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Axes object, or an array of axes objects. The contents of ax is useful for specifying the target axes when you call plotting functions within your class definition. You can also use ax to set properties on the axes.

Depending on the contents of the chart, ax might be a scalar axes object or an array of axes objects:

• If the chart does not already contain an axes object, getAxes creates a Cartesian axes and returns it as ax.
• If the chart contains one Cartesian, polar, or geographic axes object,ax is returned as that object.
• If the chart contains multiple axes objects, ax is an array of those objects.

getAxes returns only Cartesian, polar, or geographic axes objects. It does not return other types of objects that are descendents of theTiledChartLayout.

Examples

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The setup method is a common place to call plotting functions and set the axes hold state. In both cases, you must specify the target axes.

Create a setup method in your class definition file. Within that method, call getAxes to get the axes object ax. Then plot two lines by passing ax as the first argument to theplot and hold functions. Callhold(ax,'off') at the end of the method.

classdef TwoLinesPlot < matlab.graphics.chartcontainer.ChartContainer

properties
    % ...
end

methods(Access = protected)
    function setup(obj)
        % Get the axes
        ax = getAxes(obj);
        
        % Plot two lines in the axes
        line1 = plot(ax,[1 2 3 4 5],[3 5 1 4 9]);
        hold(ax,'on')
        line2 = plot(ax,[1 2 3 4 5],[30 52 21 9 18]);
        
        % Turn off hold state
        hold(ax,'off')
    end
    function update(obj)
        % ...
    end
end

end

Define a setup method in your class definition file. Within that method, call getAxes to get the axes object ax. Then set the _x_-axis color and the font angle for the axes. Callhold(ax,'on') before calling any plotting functions. Then callhold(ax,'off') at the end of the method.

classdef RedAxisPlot < matlab.graphics.chartcontainer.ChartContainer

properties
    % ...
end

methods(Access = protected)
    function setup(obj)
        ax = getAxes(obj);
        ax.XColor = [1 0 0];
        ax.FontAngle = 'italic';
        hold(ax,'on')
        
        % Call plotting functions
        % ...
        
        hold(ax,'off')
    end
    function update(obj)
        % ...
    end
end

end

Limitations

• Setting the OuterPositon, InnerPosition,Position, or PositionConstraint properties on the axes might produce unexpected results. Instead, configure the position on an instance of your chart.
• Changing the Parent property of the axes is not recommended. Instead, specify the Parent property on an instance of your chart.

Version History

Introduced in R2019b

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When you call the getAxes method in a chart that inherits frommatlab.graphics.chartcontainer.ChartContainer, the method now returns an axes object that is a child of a TiledChartLayout object. If there are no axes in the chart, getAxes creates a Cartesian axes object. The chart no longer has an axes object until you create one by calling the getAxes method or one of the axes creation functions: axes,polaraxes, or geoaxes.

As a consequence of these changes, the axes in your chart might not be the current axes. Your code might produce unexpected results if you call the following types of functions within your class methods without specifying the target axes object.

• Plotting functions — For example, plot,scatter, bar, orsurf
• Functions that modify the axes — For example, hold,grid, or title

In R2019b, the axes object is a child of the chart object, and it is the current axes within the scope of your class methods.

To update your code, specify the axes object as the first input argument when calling plotting functions and functions that modify the axes.