how to only clear data in fig

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Hi

i wnat to clear only data in fig

I try to cla reset but this command all initializes another settings.

i wnat remain other setting (ex. xlim, view etc...)

Eventually , I want animate rotating circle Thanks for your review

%%
clear all;
clc;
close all;
%%
% p_circle0 = circle(1,1,1);
n_circle_p = 50;
theta_c = 0:2*pi/(n_circle_p-1):2*pi;
p_circle = zeros(n_circle_p, 3);
r = 1;
for i = 1:n_circle_p
    p_circle(i,:) = [r*cos(theta_c(i)), r*sin(theta_c(i)), 0];
end
% p_circle = [p_circle0, zeros(size(p_circle0,1),1)];
N = size(p_circle,1);
N_sample = 10;
theta = 0:pi/(N_sample-1):pi;
fig1 = figure(1);
    p_circle2 = zeros(size(p_circle));
    for i = 1:N
        p_circle2(i,:) = (rotx(theta(1))*p_circle(i,:)')';
    end
    line(p_circle2(:,1),p_circle2(:,2),p_circle2(:,3));
    grid on;
    xlim([-1.5, 1.5]);
    ylim([-1.5, 1.5]);
    zlim([-1.5, 1.5]);
    xlabel('x');
    ylabel('y');
    zlabel('z');
    view([30, 40]);
    
%%
for j = 1:N_sample
    p_circle2 = zeros(size(p_circle));
    for i = 1:N
        p_circle2(i,:) = (rotx(theta(j))*p_circle(i,:)')';
    end
    line(p_circle2(:,1),p_circle2(:,2),p_circle2(:,3));
    line(p_circle2(1:2,1),p_circle2(1:2,2),p_circle2(1:2,3), 'Color', 'r');
        grid on;
    xlim([-1.5, 1.5]);
    ylim([-1.5, 1.5]);
    zlim([-1.5, 1.5]);
    xlabel('x');
    ylabel('y');
    zlabel('z');
    view([30, 40]);
    pause(0.5);
    cla reset;
    drawnow  % display updates
end

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Answer 1

Voss on 28 Feb 2022

Edited: Voss on 28 Feb 2022

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Seems like your best bet in this situation would be to create those lines before your for loop and then set their XData, YData, ZData inside the loop. Something like this:

my_lines = [line() line('Color','r')];
for j = 1:N_sample
    
    % calculate p_circle2
    
    set(my_lines(1), ...
        'XData',p_circle2(:,1), ...
        'YData',p_circle2(:,2), ...
        'ZData',p_circle2(:,3));
   
    % similarly for my_lines(2)
    
end

instead of doing cla reset or similar.

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HyunukSeo on 28 Feb 2022

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I don't understand what your code means

Couldn't apply but thank you so much

Now I have roughly achieved my goal

The problem was the location of the cla reset

I still haven't found a better way than cla reset

If there is a way to delete only data other than cla reset

I think it would be really convenient.

clear;
clc;
close all;
%Make Circle
center=[0 1];  
n_circle_p = 40;
theta_c = 0:2*pi/(n_circle_p-1):2*pi;
    %First Circle
    p_circle = zeros(n_circle_p, 3);
    r = 1;
    for i = 1:n_circle_p
        p_circle(i,:) = [r*cos(theta_c(i))+center(1), r*sin(theta_c(i))+center(2), 0];
    end
    %First Circle
    s_circle = zeros(n_circle_p, 3);
    r = 0.8;
    for i = 1:n_circle_p
        s_circle(i,:) = [r*cos(theta_c(i))+center(1), r*sin(theta_c(i))+center(2), 0];
    end
%Rotate resolution(deg 0 to deg PI)
N = size(p_circle,1);
N_sample = 20;
theta = 0:2*pi/(N_sample-1):2*pi;
%Rotate resolution(deg 0 to deg PI)
cLINE_L = 40;
cLINE   = zeros(cLINE_L, 3); 
cLINE(:,1) = transpose(linspace(1.5,-1.5,40));
%Draw Setup
redstart = 1;
redend   = 20;
kstart = 21;
kend   = 40;
lim_min = -5;
lim_max = 5;
while true
    for j = 1:N_sample
        p_circle2 = zeros(size(p_circle));
        s_circle2 = zeros(size(s_circle));
        for i = 1:N
            p_circle2(i,:) = (rotx(theta(j))*p_circle(i,:)')';
            s_circle2(i,:) = (rotx(theta(j))*s_circle(i,:)')';
        end
        
        line(p_circle2(:,1),p_circle2(:,2),p_circle2(:,3));
        line(s_circle2(:,1),s_circle2(:,2),s_circle2(:,3));
        line(p_circle2(redstart:redend,1),p_circle2(redstart:redend,2),p_circle2(redstart:redend,3), 'Color', 'r');
        line(p_circle2(kstart:kend,1),p_circle2(kstart:kend,2),p_circle2(kstart:kend,3), 'Color', 'k');
        line(cLINE(:,1),cLINE(:,2),cLINE(:,3))
        
        grid on;
        xlim([lim_min, lim_max]);
        ylim([lim_min, lim_max]);
        zlim([lim_min, lim_max]);
        xlabel('x');
        ylabel('y');
        zlabel('z');
        view([45, 45]);
        
        drawnow  % display updates
    
        pause(0.1);
%         if j ~= N_sample
                cla reset;
%         end
    end
end

Voss on 28 Feb 2022

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As I understand the problem, it was that cla or cla reset changes axes settings that you don't want changed, and you asked whether there is a way to just clear the plot (i.e., delete the lines) but keep the axes settings the same.

Yes, you can avoid changing any axes settings at all by operating on the lines in the axes directly: specifically, by storing the lines' handles returned from the line() function and calling delete() on them when you want to delete those lines. But the better way is to create the lines one time and update them each time through your for loop, rather than deleting them and recreating them each time through.

Here's how this approach might look applied to the while true/for loop in the second half of the code from your most recent comment:

clear;
clc;
close all;
%Make Circle
center=[0 1];  
n_circle_p = 40;
theta_c = 0:2*pi/(n_circle_p-1):2*pi;
    %First Circle
    p_circle = zeros(n_circle_p, 3);
    r = 1;
    for i = 1:n_circle_p
        p_circle(i,:) = [r*cos(theta_c(i))+center(1), r*sin(theta_c(i))+center(2), 0];
    end
    %First Circle
    s_circle = zeros(n_circle_p, 3);
    r = 0.8;
    for i = 1:n_circle_p
        s_circle(i,:) = [r*cos(theta_c(i))+center(1), r*sin(theta_c(i))+center(2), 0];
    end
%Rotate resolution(deg 0 to deg PI)
N = size(p_circle,1);
N_sample = 20;
theta = 0:2*pi/(N_sample-1):2*pi;
%Rotate resolution(deg 0 to deg PI)
cLINE_L = 40;
cLINE   = zeros(cLINE_L, 3); 
cLINE(:,1) = transpose(linspace(1.5,-1.5,40));
%Draw Setup
redstart = 1;
redend   = 20;
kstart = 21;
kend   = 40;
lim_min = -5;
lim_max = 5;
% set the axes settings first:
grid on;
xlim([lim_min, lim_max]);
ylim([lim_min, lim_max]);
zlim([lim_min, lim_max]);
xlabel('x');
ylabel('y');
zlabel('z');
view([45, 45]);
% create the lines you need now.
% only need to specify their color, no data yet (except for the last one
% (cLINE), whose data does not change inside the for loop)
my_lines = [ ...
    line() ...
    line() ...
    line('Color','r') ...
    line('Color','k') ...
    line( ...
        'XData',cLINE(:,1), ...
        'YData',cLINE(:,2), ...
        'ZData',cLINE(:,3)) ...
    ];
while true
    
    for j = 1:N_sample
        
        p_circle2 = zeros(size(p_circle));
        s_circle2 = zeros(size(s_circle));
        for i = 1:N
            p_circle2(i,:) = (rotx(theta(j))*p_circle(i,:)')';
            s_circle2(i,:) = (rotx(theta(j))*s_circle(i,:)')';
        end
        
        % now set the lines' data. that is, update the existing 
        % lines from the new p_circle2 and s_circle2
        set(my_lines(1), ...
            'XData',p_circle2(:,1), ...
            'YData',p_circle2(:,2), ...
            'ZData',p_circle2(:,3));
        set(my_lines(2), ...
            'XData',s_circle2(:,1), ...
            'YData',s_circle2(:,2), ...
            'ZData',s_circle2(:,3));
        set(my_lines(3), ...
            'XData',p_circle2(redstart:redend,1), ...
            'YData',p_circle2(redstart:redend,2), ...
            'ZData',p_circle2(redstart:redend,3));
        set(my_lines(4), ...
            'XData',p_circle2(kstart:kend,1), ...
            'YData',p_circle2(kstart:kend,2), ...
            'ZData',p_circle2(kstart:kend,3));
        
        drawnow  % display updates
        pause(0.1);
        
    end
end

HyunukSeo on 28 Feb 2022

Open in MATLAB Online

Wow, that's right.

'delete()' is the way I think it is.

But I think the method you suggested is nicer.

This is where I first learned how to use 'set'.

thank you so much.

In addition, to move more smoothly

Starting with J at 2, it was perfect.

while true
    
    for j = 2:N_sample
        
        p_circle2 = zeros(size(p_circle));
        s_circle2 = zeros(size(s_circle));
        for i = 1:N
            p_circle2(i,:) = (rotx(theta(j))*p_circle(i,:)')';
            s_circle2(i,:) = (rotx(theta(j))*s_circle(i,:)')';
        end
        
        % now set the lines' data. that is, update the existing 
        % lines from the new p_circle2 and s_circle2
        set(my_lines(1), ...
            'XData',p_circle2(:,1), ...
            'YData',p_circle2(:,2), ...
            'ZData',p_circle2(:,3));
        set(my_lines(2), ...
            'XData',s_circle2(:,1), ...
            'YData',s_circle2(:,2), ...
            'ZData',s_circle2(:,3));
        set(my_lines(3), ...
            'XData',p_circle2(redstart:redend,1), ...
            'YData',p_circle2(redstart:redend,2), ...
            'ZData',p_circle2(redstart:redend,3));
        set(my_lines(4), ...
            'XData',p_circle2(kstart:kend,1), ...
            'YData',p_circle2(kstart:kend,2), ...
            'ZData',p_circle2(kstart:kend,3));
        
        drawnow  % display updates
        pause(0.1);
        
    end

Voss on 28 Feb 2022

I'm glad it's working!

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how to only clear data in fig

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