x0 = 32.d
y0 = 54.d  ; x and y pos of center

r = 10.d ; radius
phi = 32./!radeg ; phase of rotation in radians
omega = (5./!radeg) ; 10 degrees per time unit 
t = dindgen(30)

x = x0 + r*sin(omega*t + phi) + randomn(seed,30)*0.3
y = y0 + r*cos(omega*t + phi) + randomn(seed,30)*0.3

xerr = make_array(30,value=0.3,/double)
yerr = make_array(30,value=0.3,/double)

save,file='circdata.sav',t,x,y,xerr,yerr

print,'New circle data saved.'

end