color area between two shapes

I have two shapes and I want to color the area between them

The first shape is a circle of Radius R=10 for example and with center (0,0), and the second shape is a random shape but surrounds the cirle and may have communs points, but it is impossible to have points inside the circle (as in the picture).

As example for real data that I have:

load('data.mat');  % load the coordinates of the second random shape represented as 'xfs' and 'yfs'

%%%%%%%%% create the circle %%%%%%%%%%
R = 10; C = [0. 0.] ;
xcf = C(1)+R*cos(linspace(0,2*pi,length(xfs))) ;
ycf = C(2)+R*sin(linspace(0,2*pi,length(xfs))) ;

[Star Strider]

It is not possible to read the attached file. I tried several different ways to open it and all attempts failed.

Try saving it again as a .mat file, rather than giving it a .m suffix.

[Khoder Makkawi]

Ok sorry it was my fault, could you try now please

[Matt J]

The data.mat file does not contain data resembling the posted shape.

[Khoder Makkawi]

the data file contain the x and y coordinates for the points of the posted shape. For each value in "x" it corresponds to a value in "y" at the same index.

[Matt J]

Let's plot it right now:

load(websave('t','https://www.mathworks.com/matlabcentral/answers/uploaded_files/592700/data.mat'))

scatter(xfs,yfs)

[Khoder Makkawi]

It was the wrong data I saved in the second time sorry again.

These are the right coordinates.

I modified the file.

Answer 1

[Matt J]

load(websave('t','https://www.mathworks.com/matlabcentral/answers/uploaded_files/592785/data.mat'))

R = 10; C = [0. 0.] ;
xcf = C(1)+R*cos(linspace(0,2*pi,length(xfs))) ;
ycf = C(2)+R*sin(linspace(0,2*pi,length(xfs))) ;

shpOuter=polyshape(xfs,yfs);
shpInner=polyshape(xcf,ycf);

Warning: Polyshape has duplicate vertices, intersections, or other inconsistencies that may produce inaccurate or unexpected results. Input data has been modified to create a well-defined polyshape.

plot(shpOuter,'FaceColor','none');
hold on
plot(shpInner,'FaceColor','none');
plot(subtract(shpOuter,shpInner))
hold off

[Khoder Makkawi]

Hello Matt,

I am receiving this message: "Undefined function or variable 'polyshape'."

So could you send me the function please.

[Matt J]

polyshape was introduced in R2017b

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

[Khoder Makkawi]

That's exactly what I want, but the problem is that I have R2016a so there is no solution to have this function?

[Matt J]

No. You should upgrade. There have been lots of important new features added since R2016a.

[Khoder Makkawi]

ok Thank you I will try to upgrade.