CODEWITHSUNDEEP
matlabgraphicsmatlab-figure
EddyTheB
EddyTheB

Reputation: 3200

Replot a deleted object MATLAB

Is it possible to replot a line after it has been deleted, using properties previously retrieved by 'get()'.

For example:

% Create the plot and 'get' its properties.
axes
P = plot(1:360, sind(1:360));
PG = get(P);

% Delete the plot.
delete(P)

% Replot the line...
plot(PG)  % ?????

I'd like it to be generalizable, i.e. the solution would work for surface plots, line plots, text annotations, etc.

Upvotes: 3

Views: 496

Answers (2)

Luis Mendo
Luis Mendo

Reputation: 112659

Approach 1: Don't delete it, make it invisible

Instead of deleting and recreating the object, you could make it invisible:

set(P, 'visible', 'off')

and then visible again

set(P, 'visible', 'on')

Approach 2: Create object and set property values with loop

If you really want to recreate a deleted object, you can proceed as follows: create an object of the same type and use a for loop to set its properties to the stored values. A try-catch block is needed because some properties are read-only and issue an error.

%// Replot the object...
Q = plot(NaN); %// create object. Plot any value
fields = fieldnames(PG);
for n = 1:numel(fields)
    try
        set(Q, fields{n}, getfield(PG, fields{n})); %// set field
    catch
    end
end

You can use this approach with other types of graphics objects, such as surf, but then you have to change the line that creates the object (first line in the code above). For example, with surf it would be something like

Q = surf(NaN(2)); %// create object. surf needs matrix input

I have tested this in R2010b with plot and with surf.

Approach 3: Make a copy of the object and restore it, using copyobj

Use copyobj to make a copy of the object in another (possibly invisible) figure, and then recover it from that. This automatically works for any object type.

%// Create the plot
P = plot(1:360, sind(1:360));
a = gca; %// get handle to axes

%// Make a copy in another figure
f_save = figure('visible','off');
a_save = gca;
P_saved = copyobj(P, a_save);

%// Delete the object
delete(P)

%// Recover it from the copy
P_recovered = copyobj(P_saved, a);

Upvotes: 5

Matt
Matt

Reputation: 13923

You can simply store the object as a struct PG with the get-command (as you already did) and then set all the parameters at once with the set-command. There are some read-only fields, that need to be removed before setting them and the objects must be of the same type. In the following example, we create a plot with plot(0) that is being overwritten with the data from the previous plot.

% Create the plot
figure
P = plot(1:360, sind(1:360));

% Store plot object
PG = get(P);

% Delete the plot
delete(P);

% Remove read-only fields of plot object
PG = rmfield(PG,{'Annotation','BeingDeleted','Parent','Type'});

% Create a new plot
figure
P = plot(0);

% Set the parameters
set(P,PG);

If you don't want to manually remove the fields, use a try-catch-block and iterate over all the fields as described in Luis Mendo's answer.

Upvotes: 1

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