MATLAB: How to manipulate the properties of a polar graph

handlepolar

I am ploting a polar graph and would like to change various properties. Mainly remove and/or the polar axis labels.

I manage to get the gca handles, but I am not able to find which one correspond to these properties.

Thank you

Best Answer

The labels for the radius and angle are TEXT objects with the 'HandleVisibility' set to 'off'. You can get their handles by:

AllText = findobj(allchild(gca), 'flat', 'type', 'text');

It might be easier to create a local copy of "polar.m" using a new name and disable the creation of the labels manually. Or you can add the tag 'radius_label' to the radius labels, such that you can let the above FINDOBJ command find them.

Related Solutions

MATLAB: How to ensure the polar axes lines remain visible after I overlay the polar axes with a contour plot in MATLAB 7.6 (R2008a)

Polar axes created by the POLAR function in MATLAB 7.6 (R2008a) are simply a set of patch, line and text objects drawn in the right regions to make it look like an axis. This is different from the regular non-polar axes grid lines which are not objects in the handle graphics hierarchy and rendered differently. Therefore, when the contour is overlaid on the polar axes, it hides the grid line and text objects underneath it.

To display the axes grid lines and text objects you will need to extract their handles and set their move them to the top of the graphics hierarchy using UISTACK when all other plotting is complete. For example,

polar(0,0);
hold on
% Extract handles to polar grid lines and text labels
set(0,'ShowhiddenHandles','on');
polarline = findobj(gca,'type','line');
polartext = findobj(gca,'type','text');
set(0,'ShowhiddenHandles','off');
n = 6; r = (0:n)'/n; theta = pi*(-n:n)/n;
X = r*cos(theta); Y = r*sin(theta); C = r*cos(2*theta);
pcolor(X,Y,C)
% Move the polar grid lines to the top
uistack(polarline,'top');
uistack(polartext,'top');

In addition, you could also set the object's EraseMode property to 'xor' which instrucst MATLAB to render them with a color that contrasts whatever is underneath it. Note that the axes grid line colors will no longer be black in all areas.

% Change EraseMode property of objects
set(polarline,'EraseMode','normal');
set(polartext,'EraseMode','xor');

For more information on UISTACK, line properties, text properties and displaying contours in polar coordinates, consult the documentation by executing,

doc uistack

doc line_props

doc text_props

web([docroot '/techdoc/creating_plots/f10-2524.html#f10-2674'])

MATLAB: How to remove the formula text

After the ezpolar() call,

delete(findobj(gca, 'type', 'text'))

This works because the text() that is created with the formula has a visible handle, where-as the text() objects created for the various labels have hidden handles.

Best Answer

Related Solutions

MATLAB: How to ensure the polar axes lines remain visible after I overlay the polar axes with a contour plot in MATLAB 7.6 (R2008a)

MATLAB: How to remove the formula text

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