Create a plot of points on a circumference separated by radii

Hello. I need some help for realizing a plot.

Have you any idea about how to plot a circumference with points and radii as the one in this image?

Answer 1

[Dyuman Joshi]

You can use a set of points and polarscatter to achieve this.

What have you attempted yet?

[Lorenzo Lellini]

I tried this but the radii are not between the points but over them

% Parametri del plot
numCircles = 10;    % Numero di circonferenze concentriche
numPoints = 20;     % Numero di punti tra una corona e l'altra

% Calcola i raggi delle circonferenze concentriche
radii = linspace(0.1, 1, numCircles);

% Calcola gli angoli per i punti su ogni circonferenza
angles = linspace(0, 2*pi, numPoints+1);
angles = angles(1:end-1);

% Inizializza la figura
figure(1);
hold on;
axis equal;
grid on;

% Disegna le circonferenze concentriche
for i = 1:numCircles
    r = radii(i);
    theta = linspace(0, 2*pi, 100);
    x = r * cos(theta);
    y = r * sin(theta);
    plot(x, y, 'k');
end

% Disegna i punti tra le circonferenze
for i = 1:numCircles-1
    r1 = radii(i);
    r2 = radii(i+1);
    theta1 = linspace(0, 2*pi, numPoints+1);
    theta1 = theta1(1:end-1);
    theta2 = linspace(0, 2*pi, numPoints+1);
    theta2 = theta2(1:end-1);
    x1 = r1 * cos(theta1);
    y1 = r1 * sin(theta1);
    x2 = r2 * cos(theta2);
    y2 = r2 * sin(theta2);
    
    midX = (x1 + x2) / 2;
    midY = (y1 + y2) / 2;
    plot(midX, midY, 'k.', 'LineWidth', 5);
end

% Disegna i raggi che collegano i punti sfasati di un angolo
for i = 1:numCircles-1
    r1 = radii(i);
    r2 = radii(i+1);
    theta1 = linspace(0, 2*pi, numPoints+1);
    theta1 = theta1(1:end-1);
    theta2 = linspace(0, 2*pi, numPoints+1);
    theta2 = theta2(1:end-1);
    x1 = r1 * cos(theta1);
    y1 = r1 * sin(theta1);
    x2 = r2 * cos(theta2);
    y2 = r2 * sin(theta2);
    
    angleDiff = (theta2 - theta1) / 2;
    newTheta = theta1 + angleDiff;
    endX = r2 * cos(newTheta);
    endY = r2 * sin(newTheta);
    
    for j = 1:numPoints
        plot([x1(j) endX(j)], [y1(j) endY(j)], 'k');
    end
end

hold off

xlim([-1 1])
ylim([-1 1])

% Aggiungi titolo e label agli assi
% xlabel('X');
% ylabel('Y');

[Dyuman Joshi]

That seems quite complicated.

Here's a simplified approach -

%Number of points
n=5;
%Range of angles
theta = 0:30:360;
%Range of radii
r = 0:n-1;

%Generating the set of points
[R,THETA]=meshgrid(r, theta);

%plotting the points 
polarscatter(deg2rad(THETA), R, [], [0 0 0], 'filled')
%Modify ticks and tick labels as per requirement
thetaticks(15:30:360)
rticklabels([])

[Dyuman Joshi]

Hello @Lorenzo Lellini, did you check my answer?

[John D'Errico]

@Dyuman Joshi - this seems almost spot on. But you might change the circumferential ticks, to leave each point appear to be inside a region, not on an edge.

%Number of points
n=5;
%Range of angles
theta = 0:30:360;
%Range of radii
r = 0:n-1;
%Generating the set of points
[R,THETA]=meshgrid(r, theta);
%plotting the points 
polarscatter(deg2rad(THETA), R, [], [0 0 0], 'filled')
%Modify ticks and tick labels as per requirement
thetaticks(15:30:360)
rticks([1/2:n-1/2]) % Different

I changed only the very last line from what you did.

[Dyuman Joshi]

@John D'Errico, You are, of course, right that my answer is a bit incomplete.

The thing is, I was not sure if I wanted to do give the full solution and thought OP will figure it out based on my comments, so I left some bits.