Can I draw the figure with the help of MATLAB code ?

I want to figure out the following graph to show map between two annular region as follows:

Here B is subset of A and we want to show the map from (A - B) to B.

How do I plot this graph?

Can I draw the figure with the help of MATLAB code or Mathematica ?

In that case what would be the Matlab Code ?

Help me

Answer 1

[Star Strider]

Try this:

circx = @(r,a) r.*cos(a); 
circy = @(r,a) r.*sin(a);
a = linspace(0, 2*pi);

figure
fill(0.2*circx(1,a)-0.5, 0.2*circy(1,a), 'g')
hold on
fill(0.1*circx(1,a)-0.5, 0.1*circy(1,a), 'w')
fill(0.2*circx(1,a)+0.5, 0.2*circy(1,a), 'g')
fill(0.1*circx(1,a)+0.5, 0.1*circy(1,a), 'w')
hold off
axis equal
xlim([-1 1])
annotation('textarrow',[0.35, 0.7], [0.58, 0.58])
text(-0.6, 0.15, 'A-B')
text([-0.5 0.5], [0 0], 'B', 'HorizontalAlignment','center')
text(0, 0.2, '\itf\rm', 'FontSize',15)

Experiment to get the result you want.

[Mabud Sarkar]

Thank you for your answer. But how the arrow will touch the circle B or enter into it and how to input the letter/name A outside the large circle ?

[Star Strider]

To change the arrow, use this instead:

annotation('textarrow',[0.35, 0.7], [0.58, 0.52])

To label each circle ‘A’ above it, add this line:

text([-0.5 0.5], [0.25 0.25], 'A', 'HorizontalAlignment','center')

Those changes should do what you want:

[Mabud Sarkar]

Thank you very much.

Actually I want add two more arraow as see the following graph:

How do I get other two arraow from B to B and from A to B ?

Please help me with this question.

[Star Strider]

As always, my pleasure.

Slightly adjust the existing annotation call, and add two others, so there are three total, one for each arrow:

annotation('textarrow',[0.35, 0.7], [0.58, 0.54])
annotation('textarrow',[0.35, 0.7], [0.52, 0.52])
annotation('textarrow',[0.35, 0.7], [0.46, 0.50])

That should do what you want.

[Mabud Sarkar]

Many many thanks to you. Can you help me with last question ?

How are chosing the annotation?

Are you chossing the starting point and ending point?

But in your first figure teh starting point on the left is (-0.4, 0.2) but you wrote different point.

Please explain the process.

Next and important question is-

What would be the Matlab code if the Right side sets has different "name" as below:

i.e., A-B is going to the set "F" and the outside set on right side is E.

Which new the annotations would be requred here?

Please help me with this last question.

[Star Strider]

Two of the text calls do not change, however two now do change.

All of them are now:

text(-0.6, 0.15, 'A-B')
text([-0.5 0.5], [0 0], {'B','F'}, 'HorizontalAlignment','center')
text(0, 0.2, '\itf\rm', 'FontSize',15)
text([-0.5 0.5], [0.25 0.25], {'A','E'}, 'HorizontalAlignment','center')

That should do what you want.

[Mabud Sarkar]

In your 1st answer, you used

text([-0.5 0.5], [0 0], 'B', 'HorizontalAlignment','center')

Why did you use both [-0.5 0.5] and [0 0] ?

But in the previous line you used only

text(-0.6, 0.15, 'A-B')

Can you please explain the above ?

Second question,

why in case of annotation textarrow, we are allowed only points between 0 and 1 ?

Why not negative points ?

[Star Strider]

They are two separate text calls displaying two different strings.

The ‘B’ is displayed twice, once in each circle, so two positions, one for each. (I could have used two different text calls. Using one text call with two coordinates is more efficient.)

The ‘A-B’ is displayed once, so it only needs one set of coordinates.

Answer 2

[KALYAN ACHARJYA]

Please note: I have done the Jugaad here. I have no idea what the plot represents?

I tried it for 10 minutes, hence I posted it as 2nd answer.

x=[5,5,15,15];
y=[5,5,5,5];
r=[2,1,2,1];
theta=0:pi/50:2*pi;
for i=1:4
x_circle=r(i)*cos(theta)+x(i);
y_circle = r(i)*sin(theta)+y(i);
plot(x_circle,y_circle);
if r(i)==max(r)
h=fill(x_circle,y_circle,'g');
else
 h=fill(x_circle,y_circle,'w');    
end
hold on;
end
text(x(1),y(1)+3,'A');
text(x(1),y(1)+1.5,'A-B');
text(x(3),y(3)+3,'A');
text(x(1),y(1),'B');
text(x(3),y(3),'B');
quiver(x(1)+1.3,y(1),10,0);
text(10,5.3,'f');

[Mabud Sarkar]

Thank you for your answer. But how the arrow will touch the circle B ?

Actually this figures represnts mapping between two annular region in Complex analysis of M.Sc. mathematics ?

Answer 3

[Steven Lord]

A regular N-sided polygon (for large N) is visually indistinguishable from a circle. Try:

>> A = nsidedpoly(1000, 'Center', [0 0], 'Radius', 2);
>> B = nsidedpoly(1000, 'Center', [0 0], 'Radius', 1);
>> C = subtract(A, B);
>> plot(C, 'FaceColor', 'g')
>> axis equal

To make copies of the polyshape objects A and B at a different location, call translate on them (specifying a different variable name as output.) See this documentation page for more functions that you can use to operate on polyshape objects.

For the arrow, call annotation. For the letters, call text.

[Mabud Sarkar]

Please add the rest code because I can not get it at the beginning. However I will grasp the code for future. So please add the complete code with the figure.