plotting a surface between two curve

Hi all,

I have plotted two curves by importing data. The first curve, referred to as the small curve, consists of the points (x1, y1, z1), while the second curve, the large curve, is composed of the points (x2, y2, z2), as illustrated in the figure.

To create these curves, I imported the data from the attached small.txt and large.txt files. However, as I did not require the first columns of the data, and they needed to be fixed values (0.1577 and 0.1590, respectively), I utilized the following code:

Small curve:

aa1 = readtable(file_address);
n=size(aa1.Var1,1);
x1=ones([n,1])*0.1577;
y1=aa1.Var3;
z1=aa1.Var2;
ff=figure(11);
plot3(x1,y1,z1)

Large curve

aa2 = readtable(file_address);
n=size(aa2.Var1,1);
x2=ones([n,1])*0.1590;
y2=aa2.Var3;
z2=aa2.Var2;
ff=figure(11);
plot3(x2,y2,z2);

I am interested in connecting these two curves together using a surface that takes on the shape of a cone, similar to the one shown in the second picture. Can you please guide me on how to accomplish this?

Thank you in advance for any assistance you can provide.

[M]

Thanks for the suggestion. I attached data as well as code for generating those curves.

Answer 1

[Paul]

Hi M,

Here's some code to get started.

% small curve
file_address = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/1350204/small.txt';
aa1 = readtable(file_address);
n=size(aa1.Var1,1);
x1=ones([n,1])*0.1577;
y1=aa1.Var3;
z1=aa1.Var2;
%Large curve
file_address = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/1350209/large.txt';
aa2 = readtable(file_address);
n=size(aa2.Var1,1);
x2=ones([n,1])*0.1590;
y2=aa2.Var3;
z2=aa2.Var2;

figure;
hold on
plot3(x1,y1,z1)
plot3(x2,y2,z2);
surf([x1 , x2].', [y1 , y2].' , [z1 , z2].','FaceColor','r','EdgeColor','none')

view(3)

Play around with the number of points used in the surf and the surface properties and the view to get the results you want.