Trying to plot a 3d closed cylinder

I tried many options but I can't get a 3d closed cylinder. I only get hollow cylinder.

Trying to get something like this:

But getting this:

Can someone please help me.

My code:

[x1 y1] = GetCircle(1, 0, 0, 0, 2*pi);
z1 = zeros(1, length(x));
z2 = ones(1, length(x));

x = [x1;x1];
y = [y1;y1];
z = [z1;z2];

surf(x,y,z);

where GetCircle() is:

function [x y] = GetCircle(r, h, k, a, b)
    t = linspace(a, b, 50);
    x = r*cos(t) + h;
    y = r*sin(t) + k;
end

[Azzi Abdelmalek]

Post your code.

Answer 1

[Azzi Abdelmalek]

To do this you could use cylinder function

r=2
[X,Y,Z] = cylinder(r)
h=mesh(X,Y,Z,'facecolor',[1 0 0])

For what you are looking for, if you have a VRML tool box, you can get the same cylinder. Can you tell what this cylinder is for?

[Maor Levy]

Thanks Azzi,

But the code you gave still produce hollow cylinder.

I'm taking intro to graphics class and we need to construct a model of the Pantheon (Rome).

Like this: http://www.cis.temple.edu/~hughes/cs3219/pantheon.bmp

So I'm trying to do the columns.

[Azzi Abdelmalek]

Look at Simulink 3D animation, you will find a VRML language which allows to create 3D object, and even animate them in simulink.

[Maor Levy]

Yes, but it's the first lab and the professor doesn't want us to use Simulink.

Let's say, I don't mind it will be hollow, since I'm plotting on top of it. How can I produce in a loop cylinders, one next to each other(to crate the columns)?

[Azzi Abdelmalek]

r=0.5
[X,Y,Z] = cylinder(r)
for k=1:5
h=mesh(X,Y,Z,'facecolor',[0 1 1])
hold on
X=X+1
end

[Maor Levy]

Thank you.

Answer 2

[Sharanya Srinivas]

To create an illusion of a solid cylinder, you have to fill in the floor and ceil of the cylinder. You can do so using

r = 2; n = 100;   
[X,Y,Z] = cylinder(r,n);

figure;  
surf(X,Y,Z,'facecolor','r','LineStyle','none');
hold on
fill3(X(1,:),Y(1,:),Z(1:),'r')
fill3(X(2,:),Y(2,:),Z(2,:),'r')

Answer 3

[Md Mohinoddin]

r=0.5 [X,Y,Z] = cylinder(r) for k=1:5 h=mesh(X,Y,Z,'facecolor',[0 1 1]) hold on X=X+1 end

Answer 4

[Md Mohinoddin]

[x1 y1] = GetCircle(1, 0, 0, 0, 2*pi); z1 = zeros(1, length(x)); z2 = ones(1, length(x)); x = [x1;x1]; y = [y1;y1]; z = [z1;z2]; surf(x,y,z);

Answer 5

[Kimberly Nowak]

Habt ihr eine idee wo der fehler liegt?

Aufgabe ist folgende:

Kreise zeichnen (3.27) Schreiben Sie eine Funktion [x,y]=getCircle(mittelpunkt, radius), die Ihnen die x- und y-Koordinante eines Kreises mit dem genannten Mittelpunkt und Radius zurückgibt. Verwenden Sie hierfür die folgende Transformation:

x=r*cos(t)+xm

y=r*sin(t)+ym

mit t[0,2*pi]

function [x,y] = getCircle(mittelpunkt, radius)

numPunkt = 1000;

t = linspace(0,2*pi,numPunkt);

x = radius*cos(t)' + mittelpunkt(1);

y = radius*sin(t)' + mittelpunkt(2);

end

[Sharanya Srinivas]

The function does work the way you are expecting. It might have to do with how you are calling it.

clear; close all; 
mittelpunkt = [5,5] ; 
radius = 5 ; 

[x,y] = getCircle(mittelpunkt, radius); 

figure; 
plot(x,y,'r')
hold on; plot(mittelpunkt(1),mittelpunkt(2),'b*')
xlabel('x'); ylabel('y')
title('Circle')