draw a simple complex function

assume z0 = x0 + y0 * i;

if abs(z-z0)=R

then abs(z-z0)-R describes a circle with center of z0 and radius of R;

how can we use matlab to draw it?

Answer 1

[madhan ravi]

By defining z as a function of x and y and using fplot()

 doc fplot

Answer 2

[Alan Stevens]

How about:

 x0 = 1; y0 = 2;
 z0 = x0 + y0*i;
 R = abs(z0);
 theta = 0:1/360:2*pi;
 x = x0 + R*cos(theta); y = y0 + R*sin(theta);
 plot(x,y)

[madhan ravi]

What about z?

[Alan Stevens]

Yes, z needs to be defined as well. I simply took it as zero here for simplicity (the main idea being the use of cos and sin theta).

Didn't think of fplot - a much better idea!