# Plotting 3D by rotate 2D plot around y-axis

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Tuan on 23 Mar 2023
Commented: Star Strider on 24 Mar 2023
I have a question to draw a 3D cup of coffe (no need to draw a handle). I think to be easy we need to draw 2 parabol ( inner and outter ) , the upper bound and bottom bound, then rotate that 2D plot around y-axis, but I dont have any idea and knowledge to do that, is there another way ? Can anyone help me with this, many thanks

Star Strider on 23 Mar 2023
Probably the easiest way is to define a cylinder and a shape vector —
yv = [linspace(0.3, 1, 50)];
ys1 = yv.*exp(-1.75*yv)*5;
ys2 = (1-exp(-25*(yv-0.3)))*0.7;
figure
plot(ys1, yv)
hold on
plot(ys2, yv)
hold off
grid
% xlim([0 1.5])
axis ('equal')
[X1,Y1,Z1] = cylinder(ys1,50);
[X2,Y2,Z2] = cylinder(ys2,50);
figure
surf(X1,Y1,Z1, 'EdgeColor','interp', 'FaceAlpha',0.5) % Outer Surface
hold on
surf(X2,Y2,Z2, 'EdgeColor','interp') % Inner Survface
patch([X1(end,:) X2(end,:)], [Y1(end,:) Y2(end,:)], [Z1(end,:) Z2(end,:)], 'r', 'EdgeColor','r') % Top Rim
patch([X1(1,:) X2(1,:)], [Y1(1,:) Y2(1,:)], [Z1(1,:) Z2(1,:)], 'b', 'EdgeColor','b') % Lower Surface
hold off
colormap(turbo)
This demonstrates the construction approach, and setting the outer ‘FaceAlphs’ value to shows the internal structure as well.
Experiment with the ‘ys1’ and ‘ys2’ shape vectors to get the result you want. To get the inner and outer thicknesses, it will likely be necessary to use two cyllinder objects with different shapes, and the hold function to plot both of them on the same axes. The patch call creating the top rim will autoomatically adapt to whatever the inner and outer contour functions are. Another patch call can provide a solid lower surface as well, if that is necessary. (I use the turbo colormap her because I like it. Choose the appropriate colormap for your plot.)
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Tuan on 24 Mar 2023
thank you a lot, that is all i need , hope you the best <3
Star Strider on 24 Mar 2023
As always, my pleasure!
Thank you! You, too!

KSSV on 23 Mar 2023
This might be useful. Checkout:
Tuan on 23 Mar 2023
Thanks but this still a static image, what i mean is create a 3D object with this

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