how can I make a colored 2D-surface in a polar plot? I want to give some labels to this polar... It is possible?

clc
c=input('How many blades are there in the blower?:');
t = 0:.01:2*pi;
if mod(c,2)==1 polar(t,(cos((c*t))),'-r') else polar(t,(cos((c/2)*t).^2),'-r') end
% find all of the text objects in the polar plot
h = findall(gcf,'type','text');
% delete the text objects
delete(h);

Answer 1

[Joseph Cheng]

the fill is a bit temperamental (does not work for odd blades). but it should be a starting point for you to look further.

clc
% c=input('How many blades are there in the blower?:');
c=randi(6,1,1);
t = 0:.01:2*pi;
if mod(c,2)==1 
    ph = polar(t,(cos((c*t))),'-r') 
else
    ph = polar(t,(cos((c/2)*t).^2),'-r') 
end

ph = 
  Line with properties:

              Color: [1 0 0]
          LineStyle: '-'
          LineWidth: 0.5000
             Marker: 'none'
         MarkerSize: 6
    MarkerFaceColor: 'none'
              XData: [1 0.9991 0.9962 0.9915 0.9849 0.9764 0.9662 0.9542 0.9405 0.9251 0.9081 0.8896 0.8696 0.8482 0.8256 0.8017 0.7767 0.7507 0.7238 0.6960 … ] (1×629 double)
              YData: [0 0.0100 0.0199 0.0298 0.0394 0.0489 0.0580 0.0669 0.0754 0.0835 0.0911 0.0983 0.1049 0.1109 0.1163 0.1212 0.1253 0.1289 0.1317 0.1339 … ] (1×629 double)

  Use GET to show all properties

% find all of the text objects in the polar plot
h = findall(gcf,'type','text');
% delete the text objects
delete(h);
patch(get(ph,'XData'), get(ph,'YData'), 'g')

fins = linspace(0,360,c+1);
for ind = 1:c
    txtx = 1.2*cosd(fins(ind));
    txty = 1.2*sind(fins(ind));
    text(txtx,txty,['fin ' num2str(ind)])
end

[Marcos Perez]

nice!!

Answer 2

[bio lim]

clc

c=input('How many blades are there in the blower?:');

t = 0:.01:2*pi;

if mod(c,2)==1 
  radius = cos(c*t);
  radius(radius <= 0) = 0;
  ph = polar(t,(radius),'-r') 
else
  ph = polar(t,(cos((c/2)*t).^2),'-r')
end

% find all of the text objects in the polar plot

h = findall(gcf,'type','text');

% delete the text objects

delete(h);
patch(get(ph,'XData'), get(ph, 'YData'), 'b')

The rest is the code from Cheng, except the 'fins' was renamed to 'Blade' as the image suggested.

fins = linspace(0,360,c+1);

for ind = 1:c
  txtx = 1.2 * cosd(fins(ind));
  txty = 1.2 * sind(fins(ind));
  text(txtx,txty,['Blade ' num2str(ind)])
end

Answer 3

[Adam Danz]

Starting in R2025a, polar axes support patch and surface objects.

Here's @Joseph Cheng's example applied to polar axes.

There's more info about patch and surface support in polar axes in the Graphics and App Building blog.

c = 8;
t = linspace(0,2*pi,1000);
pax = polaraxes(); 
if mod(c,2)==1 
    patch(pax,t,(cos((c*t))),'-r') 
else
    patch(pax,t,(cos((c/2)*t).^2),'-r') 
end

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