MatLab code for generating a surface as shown in the attached figure: an ellipse in the X-Y plane is twisted by 90deg as it progresses along Z-axis.

[Rena Berman]

(Answers dev) restored question

Answer 1

[Walter Roberson]

As an approximation:

[TH,R] = ndgrid(linspace(0,pi/2,200),linspace(10,22,200));
Z = sin(50*TH);
[X,Y,ZZ] = pol2cart(TH,R,Z);
surf(X,Y,ZZ,'edgecolor','none')
axis equal
view(-35,66)

[mahesh babu]

thnks a lot

[mahesh babu]

sir, i have re attached the image, thank you for pointing it out :D

[Walter Roberson]

That is not the original image. The original image was much flatter than that, and the inner edge was symmetric, reaching close to 10 on the vertical and horizontal axes, the same on each, not 14 on one and 10 on the other.