MATLAB: I wanna end iteration when result cannot be changed anymore.

Question

for example

latitude=atan((Z/P)*(1-(e1*N/(N+h)))^-1)*180/pi

N=((a^2/sqrt((a^2*cos(latitude*pi/180)^2+b^2*sin(latitude*pi/180)^2))))

h=(P/(cos(latitude*pi/180))-N)

latitude_i=atan((Z/P)*(1-(e1*N/(N+h)))^-1)*180/pi

dx=latitude_i-latitude

while dx~=0

%this difference will never be zero but very close to zero. I wanna end iteration when iteration cannot change dx anymore.

do again the above equations

end

Answer 1

   dx = 5; % set initial value here
%  my_threshold = eps; % Floating-point relative accuracy
   my_threshold = 0.01; % or whatever value you choose
while dx < my_threshold
    latitude=atan((Z/P)*(1-(e1*N/(N+h)))^-1)*180/pi
    N=((a^2/sqrt((a^2*cos(latitude*pi/180)^2+b^2*sin(latitude*pi/180)^2))))
    h=(P/(cos(latitude*pi/180))-N)
    latitude_i=atan((Z/P)*(1-(e1*N/(N+h)))^-1)*180/pi
    dx=latitude_i-latitude
end