Colouring/shading of a sector of a polar representation in combination with animatedline

How do I combine the animation of an animatedline with a 30° sector? I would like the animated point of the animatedline to always be highlighted with a 30° sector (+-15°). The animated line should become longer and longer, while the sector runs along with the first point and disappears as soon as the 360° is reached. I have the following code for the animated line and for the 30° sector, but I have no idea how to combine them as described.

%polarplot
ax = polaraxes('ThetaZeroLocation', 'top');
polarplot(ax, 0, 1); 
hold on;

random_vector = 10 + (20 - 10) * rand(1, 360);
theta_rad = deg2rad(1:360);
rlim([0, max(random_vector)]); 

h = animatedline(ax, 'Color', 'b', 'LineWidth', 2);

for i = 1:length(random_vector)
    addpoints(h, theta_rad(i), random_vector(i));
    drawnow;
    pause(0.01);  
end
hold off;

%highlighted sektor 
teta= linspace(0,pi/6,500); 
rho = [0 100*ones(499,1)'];
a = polar(teta,rho);
patch( get(a,'XData'), get(a,'YData'),[0, 0.4470, 0.7410],'FaceAlpha',0.2);

Answer 1

[Ganesh]

Hi @Kalle,

Starting R2024a, you can achieve this using "polarregion()". You can use "theta_rad(i)" to find the range of theta and plot accordingly. You can use the code below:

%polarplot
ax = polaraxes('ThetaZeroLocation', 'top');
hold on;
random_vector = 10 + (20 - 10) * rand(1, 360);
theta_rad = deg2rad(1:360);
rlim([0, max(random_vector)]);
h = animatedline(ax, 'Color', 'b', 'LineWidth', 2);

% Initial sector plot (invisible at start)
sectorAngle = 15; 
sectorPlot = polarplot(ax, [0, 0], [0, 0], 'r', 'LineWidth', 2);

teta1 = 0; 
rho1 = 1;
teta2 = pi/6;
rho2 = 1;

prev = polarregion([0 pi/6], [0 max(random_vector)]);

for i = 1:length(random_vector)
    addpoints(h, theta_rad(i), random_vector(i));
    drawnow;
    pause(0.01);
    
    sectorStart = theta_rad(i) - deg2rad(sectorAngle);
    sectorEnd = theta_rad(i) + deg2rad(sectorAngle);

    prev.FaceAlpha = 0;
    prev = polarregion([sectorStart sectorEnd], [0 max(random_vector)]);

end

prev.FaceAlpha = 0;


hold off;

Please find the relevant documentation on "polarregion" below:

https://www.mathworks.com/help/matlab/ref/polarregion.html

[Kalle]

Thank you, that was very helpful.