Trouble with surf

I am trying to plot the surface of a sphere but keep running into trouble in the z variable of my code. I have tried to resize the ra variable to the same size as y and x by multiplying it by a ones vector before sending it into z. I have tried carrying out the operations in z with element wise power . and without. I am actually pretty disappointed in myself that I can not seem to figure out an easy problem such as this. I have it sized right now but z keeps getting imaginary numbers which the system will not plot. The length of ra and theta were predetermined to be 10 and 22. Here is what I have so far. Thanks in advance for any help provided.

theta=linspace(0,2*pi,22)
ra=linspace(0,1,10)  

x=(ra'*cos(theta))
y=(ra'*sin(theta))

r1=ones(22,1)*ra
r2=r1'
z=abs(sqrt(r2.^2-x.^2-y.^2))

surf(x,y,z)

Answer 1

[Andreas Goser]

Your code executes fine on my machine. z is not complex in my case.

One idea I have is, that you have multiple ABS functions on you path.

which abs -all

Should just return paths to MATLAB builtin functions. Please verify.

[Adam Anderson]

Are you getting a whole sphere or just the top half?