Hey so I am trying to code an ellipse and I was confused about the placement of my plot. Should it be before the for loop or after?

% Given Variables
a= 20; % Meters (m)
b=10; % Meters (m)
h=18; % Meters (m)
n=5; 
t=0:0.01 : 2*pi*n;
% Calculations
r= (((a*b)./(sqrt(b*cos (t)).^2))+(a*sin(t).^2)) ;
x= (r .*cos(t));
y= (r.*sin(t));
z= ((h*t)./(2*pi*n)) ;

% Plotting plot 3
figure(1)
plot3 (x,y,z)
title('A ellispe')
xlabel('x')
ylabel('y')
zlabel('z')
grid on

% Loop for N=3
N=3;
for k=1:1:N
    a2= 20*k; % Meters (m)
    b2= 10*k;% Meters (m)
    h2=18*k;% in Meters (m)
    n=5; 
    t=0:0.01:2*pi*n;
    r2= (((a2*b2)./(sqrt (b2*cos (t)).^2))+ (a2*sin(t).^2)) ;
    x2= (r2.*cos (t));
    y2= (r2.*sin(t));
    z2= ((h2*t)./ (2*pi*n)) ;
    
    % Define Meshgrid
    [xx,yy]= meshgrid(x2, y2);
    zz=xx.^2-yy.^2;
    % Plotting
    figure(2)
    plot3 (x2 ,y2 , z2)
    mesh(xx, yy, zz)
    title(' A ellispe function')
    xlabel( 'x=r*cos (t) ')
    ylabel('y=r*sin(t)')
    zlabel('= (h*t)./ (2*pi*n) ')
    grid on
    hold on
end

[Eshan Patel]

In order for the community to help, could you please give more information about the plot you are expecting? You can include the following information:

1. Why are you using 3D axis to plot an ellipse?
2. How do you want the plot to behave in 3-D?
3. What equation are you using to plot the ellipse?
4. What does your expected plot look like?

Answer 1

[Alan Stevens]

Something like this? (I've commented out your meshgrid commands as they just confuse the plot and I'm not at all clear why they are there - you can easily reinstate them if you wish).

% Given Variables
a= 20; % Meters (m)
b=10; % Meters (m)
h=18; % Meters (m)
n=5; 
t=0:0.01:2*pi*n;
% Calculations
r= a*b./sqrt( (b*cos(t)).^2+(a*sin(t)).^2 ) ;
x= (r.*cos(t));
y= (r.*sin(t));
z= ((h*t)./(2*pi*n)) ;

% Plotting plot 3
figure(1)
plot3 (x,y,z)
title('An ellipse')
xlabel('x')
ylabel('y')
zlabel('z')
grid on

% Loop for N=3
figure(2)
N=3;
for k=1:N
    a2= 20*k; % Meters (m)
    b2= 10*k;% Meters (m)
    h2=18*k;% in Meters (m)
     
    
    r2= a2*b2./sqrt( (b2*cos(t)).^2+(a2*sin(t)).^2 ) ;
    x2= (r2.*cos (t));
    y2= (r2.*sin(t));
    z2= ((h2*t)./ (2*pi*n)) ;
    
    % Define Meshgrid
%     [xx,yy]= meshgrid(x2, y2);
%     zz=xx.^2-yy.^2;
    % Plotting
    
    plot3 (x2 ,y2 , z2)    
%     mesh(xx, yy, zz)

    title(' A ellipse function')
    xlabel( 'x=r*cos (t) ')
    ylabel('y=r*sin(t)')
    zlabel('= (h*t)./ (2*pi*n) ')
    grid on
    hold on
end