Write a matlab code to plot the 3D image of the helix below:

Use the following parameters and equations that define the axes in 3D:

p=0.199; Pitch distance
a=0.02999500; Radius of the helis wire
b=0.191; Radius of the helix
n = 5, is the number of turns.
 δ =atan(p/(2*pi*b));
x’ = b + a cos(Ө)
y’ = -a sin(Ө) sin(δ)
x =x’ sin(ф)+y’ cos(ф);
y =-x’ cos(ф)+y’ sin(ф);
z =p*ф/(2*pi)+a*sin(Ө)*cos(δ);

[DGM]

Okay, I'm done. This is what I got.

What about you?

[mujtaba Ali]

Hi yes I have managed to calculate the parameters but I am not sure how to plot the 3d helix itself

I have got values for x' y' and X, Y X but dont know how to use these to plot the 3d helix

[DGM]

If your X,Y,Z are as expected, you should be able to do

surf(X,Y,Z);
axis equal

and get a basic surf plot. From there, you can make it as fancy as you want. If you have specific problems, share your work so far so that we know what's going on.

[mujtaba Ali]

when using surf (x,y,z)

an error message shows which says error surf (x,y,z)

[Image Analyst]

I think you forgot to read the last sentence of @DGM's reply. And you didn't reply to me down below in the Answers section either.

TUTORIAL: How to ask a question (on Answers) and get a fast answer

[DGM]

I can't know what's wrong if you don't post your code.

[Umer Mushtaq]

I am also having problem after getting the values of x',y',z'. x y and z. The problem is that while i am using surf(x,y,z) i am getting an error

Error using surf (line 71)

Z must be a matrix, not a scalar or vector.

[Image Analyst]

UMER! Like I said, read the last sentence of DGM's last two comments. Now, what do they say? And why do you refuse to do it even after he and I explicitly asked? So all we can assume is that you don't want to share your code and want to fix it yourself, which is fine - it's your homework after all, not ours.

[Muhammad Taimoor Adil]

Umer. You need to create meshgrid from the two parameters (theta and phi). In order to define theta and phi see answer below by Image Analyst. In the 3d paramteric equations, put the output from the meshgrid command. This will hopefully solve your problem.

Answer 1

[Image Analyst]

No thank you. It was not on my agenda for today and you're probably not allowed to turn in my work as your own anyway. So read this first:

How do I get help on homework questions on MATLAB Answers? - MATLAB Answers - MATLAB Central

and here's a hint for you in the meantime

numPoints = 1000;
theta = linspace(0, n*2*pi, numPoints);
xPrime = b + a .* cos(theta);