creata random plot

i need to create a random plot inside a circle. i used the r = a + (b-a).*rand(100,1), but it is not working as i only get the positive values. i need to make random plot from a reference node of x,y(0,0) until 10 radius. how can i do this?

Answer 1

[Wayne King]

Do you want the points to all have radius 10? or can they have random length up to 10?

If it's the former:

    phaseang = -pi+ 2*pi*rand(100,1);
    z = 10*exp(1j*phaseang);
    compass(real(z),imag(z));
    %or
    quiver(zeros(100,1),zeros(100,1),real(z),imag(z));

If the latter:

    magz = 1e-5+(10-1e-5)*rand(100,1);
    %or just magz = 10*rand(100,1);
    phaseang = -pi+ 2*pi*rand(100,1);
    z = magz.*exp(1j*phaseang);
    quiver(zeros(100,1),zeros(100,1),real(z),imag(z));

[Kugen Raj]

i want the points to have random length up to 10.

[Wayne King]

then use my second example

[Kugen Raj]

can i know what each command does. do you have any doc.

[Wayne King]

It's all in the MATLAB doc

[Kugen Raj]

i have one problem with this plotting. the plot is beyond the reference node of x,y(0,0).

[Wayne King]

what do you mean the reference node of (0,0)? All the vectors are plotted from (0,0)

[Kugen Raj]

i want my random points to be around node of (0,0) and up to length of 10. The produced points are not around the node of(0,0) but p to length of 10.