MATLAB: Drawing a semi-circle in Matlab about a point

MATLABplottingsemicircle

Hi,
There seem to be several different ways to draw a semi-circle according to google, however none of the answers seem to give me what I need.
I would like a semi-circle (from twelve to six, if it were a clock) about the point (5,4),
Does anyone know how to do this?
I have tried rectangle with curvature, polar coodinates and the equation of a circle, but something always seems to go wrong.
This gets me closest:
theta = 0:.01:pi-pi/2; y = 1.8*exp((1j)*theta)+5.8; plot(real(y),imag(y)); axis([0 28 0 15]); axis equal;
However the centre of the circle is on the x axis and not at y=4.5.
Thanks for your help.

Best Answer

th = linspace( pi/2, -pi/2, 100);
R = 1;  %or whatever radius you want
x = R*cos(th) + 5;
y = R*sin(th) + 4;
plot(x,y); axis equal;
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