fill the area between multiple curves

I created the sign of the nasa logo using eight circumference arcs. I plotted them in the same figure but i can't fill the area inside the shape. To plot the different arcs I used parametric equations so I'm not able to access the x and y coordinates all toghether.

Thanks for everyone answering!

%circle_th plots the arc using center coordinates, radius and parameter boundaries

circle_th(117.128, 218.51,131.4,293.8,329.71);

circle_th(355.217, -281.412,422.66,115.98,129.96);

circle_th(296.094, -178.16,306.27,116.91,133.9);

circle_th(-60.4339, 482.318,444.46,299.36,305.42);

circle_th(88.377, 331.462,237.7,279.27,297.24);

circle_th(222.873, -369.099,475.8, 101.67,109.43 );

circle_th(319.927, -503.795,636.82, 104.82, 113.64 );

circle_th(110.346, 282.953, 177.37,285.27,312.58 );

Answer 1

[Cameron]

The easiest way I know is to use the fill function documented here. Take all the x and y data from your arcs using

%you may have to do this between each circle_th use if you don't have
%another way of getting the x and y data
ax = gca; %get the axis with all your curves
x = ax.Children.XData; %grab x data
y = ax.Children.YData; %grab y data

You may need to adjust your curves and line them up head to tail using the flip function like this.

x1 = (1:20)';
y1 = x1.^2;
plot(x1,y1)
x2 = (10:0.5:20)';
y2 = 0.5*x2.^2+200;
hold on
plot(x2,y2)
x3 = [x1(1);x2(1)];
y3 = [y1(1);y2(1)];
plot(x3,y3)
x = [x1;flip(x2);x3];
y = [y1;flip(y2);y3];
fill(x,y,'r')
hold off

[Claudio]

I tried acquiring the x and y values using your suggestion implemented in circle_th

However it displays 'Unrecognized method, property, or field 'XData' for class 'matlab.graphics.primitive.Data'.'

Also when using the flip function to unite the x vectors it says 'Error using vertcat

Dimensions of arrays being concatenated are not consistent.'

To which I tried to preallocate everyone with the maximum size needed, but that didn't seem to work either.

It's quite the challenge for a newbie:)

 function [x,y]=circle_th(Xc,Yc,R,th0,th1)
%UNTITLED2 Summary of this function goes here
%   Detailed explanation goes here
th=th0:0.01:th1;
X=Xc+R*cosd(th);
Y=Yc+R*sind(th);
 plot(X,Y,"Color",'r');
 
    ax=gca;
    x=ax.Children.XData;
    y=ax.Children.YData;


end

[Cameron]

You should be able to do this

function [X,Y]=circle_th(Xc,Yc,R,th0,th1)
    %UNTITLED2 Summary of this function goes here
    %   Detailed explanation goes here
    th=th0:0.01:th1;
    X=Xc+R*cosd(th);
    Y=Yc+R*sind(th);
    plot(X,Y,"Color",'r');
end

then

[X1,Y1]=circle_th(117.128, 218.51,131.4,293.8,329.71);
hold on
[X2,Y2]=circle_th(355.217, -281.412,422.66,115.98,129.96);
[X3,Y3]=circle_th(296.094, -178.16,306.27,116.91,133.9);
[X4,Y4]=circle_th(-60.4339, 482.318,444.46,299.36,305.42);
[X5,Y5]=circle_th(88.377, 331.462,237.7,279.27,297.24);
[X6,Y6]=circle_th(222.873, -369.099,475.8, 101.67,109.43);
[X7,Y7]=circle_th(319.927, -503.795,636.82, 104.82, 113.64);
[X8,Y8]=circle_th(110.346, 282.953, 177.37,285.27,312.58);
hold off

fig = figure;
ax1 = axes(fig);
x = [flip(X1),X2,flip(X3),X4,flip(X5),X6,flip(X7),X8];
y = [flip(Y1),Y2,flip(Y3),Y4,flip(Y5),Y6,flip(Y7),Y8];
fill(x,y,'r','EdgeColor','none','FaceAlpha',0.3) %I added some FaceAlpha and removed the EdgeColor

[Claudio]

Yes! It worked!

Thanks I really appriciated it!