How to shade the area between two mirror curves using patch?

Hello,

I wanted to shade the area between the curve C1 and C2 shown in the figure below.

The vector for curve C2 is:

alpha = 150 : 2 : 210;

pp = [cosd(alpha')+sind(60)+0.5 sind(alpha')+cosd(60)];
pp = flip(pp);

I am trying to shade the area using patch (shaded red in figure) but getting it shaded in other adjacent parts. Please do help and if you need any other information, comment below.

[Allen]

You an find a solution to this issue at the following linked discussion.

https://www.mathworks.com/matlabcentral/answers/180829-shade-area-between-graphs

Answer 1

[Star Strider]

I am not certain how ‘C_1’ and ‘C_2’ were created, however this is one approach to filling the space between them (creating them as circle arcs):

t = linspace(-pi/4, pi/4);                              % Parameter Vector
r = 5;                                                  % Radius
x = r*cos(t);                                           % x-Coordinate Of Curves
y = r*sin(t);                                           % y-Coordinate Of Curves

xp(1,:) = x-r*1.25;                                     % Left Side ‘x’ Vector
xp(2,:) = 1.25*r-x;                                     % Right Side ‘x’ Vector

figure
plot(xp(1,:), y, '-k',    xp(2,:), y, '-k')             % Draw Curves
hold on
patch([xp(1,:) xp(2,:)], [y fliplr(y)], 'r')            % Fill Between Curves
hold off
axis('equal')

producing:

.

[Jnandeep Talukdar]

Thank you very much for your help. C1 and C2 are a bit different but I have got the idea and the code worked. Thanks again.

[Star Strider]

As always, my pleasure!