how can I generate a random angle?

I want to plot a random straight line with a fixed length based on the coordinates of a random point. Therefore I need to find a random angle. I figured everything out but the angle.

Answer 1

[Star Strider]

Try one of these:

rangrad = 2*pi*rand;                    % Radians
rangdeg = 360*rand;                     % Degrees

Experiment to get the result you want.

[Jon]

I already provided this same approach in my earlier answer. This was my approach two using the uniform distribution.

[Star Strider]

I don¹t understand what you mean by ‘earlier answer’. Was it to another question?

My Answer posted first here to this one.

[Jon]

Sorry, I guess we must have sent the answers in at almost the same time and they collided. I hadn't noticed yours until I came back later, and so I mistakenly thought it was a later post.

Answer 2

[Jon]

Use randn or rand depending upon whether you want the angles to be normally distributed or uniformly distributed.

Since randn produces values with a mean of zero and a standard deviation of 1, you must scale it to get values that are in the range of 0 to 2*pi, and since the values may in fact be larger in magnitude than that you can keep them in the range [0,2*pi] by using the mod function. Note that the result will be random, but due to the mapping to the range [0,2*pi] they will not be normally distributed

Here is some example code that would produce N random angles using randn

N = 100; % number of random angles to generate

% compute normally distributed values with zero mean and standard deviation of 2*pi
thetaNormal = 2*pi*randn(N,1);

% map them to the range [0,2*pi]
theta = mod(thetaNormal,2*pi)

Alternatively, if the uniform distribution is OK for your purposes you can do this more simply

N = 100; % number of random angles to generate

% compute uniformly distributed values ranging from 0 to 1 and scale them to range 0 to 2*pi
theta = 2*pi*rand(N,1);