Cross product in 2d and 3D

Hi

I would like to combine the distance of r and the theta in one image.

Also, I would like to do the same in 3D.

please help in easy way because I am beginner.

[x y] = meshgrid(-10:1:10,-10:1:10,-10:1:10);

r=sqrt(x.^2+y.^2);

theta=(180/pi)*atan(y./x);

figure

surf(x,y,r)

figure

surf(x,y,theta)

Regards

Dhafer

Answer 1

[Walter Roberson]

[x y] = meshgrid(-10:1:10,-10:1:10,-10:1:10);
r=sqrt(x.^2+y.^2);
theta=(180/pi)*atan(y./x);

surf(x,y,r)
hold on
surf(x,y,theta)
hold off

would put them in the same axes.

If you want them in two different axes, then

[x y] = meshgrid(-10:1:10,-10:1:10,-10:1:10);
r=sqrt(x.^2+y.^2);
theta=(180/pi)*atan(y./x);

subplot(2,1,1)
surf(x,y,r)
subplot(2,1,2)
surf(x,y,theta)

[Dhafer]

Hi Walter

Thanks for your help.

My question was about how can I calculate the r and theta togather in one answer not in add them in one figure?

can you help me please.

regards

Dhafer

[Walter Roberson]

Do you mean like,

[theta, r] = cart2pol(x, y);

[Dhafer]

thanks

Answer 2

[Dhafer]

how can create loop in mat lab in east way?

[Walter Roberson]

Usually a "for" loop is the easiest.