I can't exit from loop

I want to stop loop when Ur is equal to Uo,but it doesn't stop. For example when i put 0.015 for D, Ur is equal to Uo at Uo=544. It doesn't stop at 544 still countinues until it reach 600. And shows Ur for Uo=600. What is wrong with this code? Thank you.

function heatt= heatt(D)
  for Uo=20:600
      mc=10;
      dc=866;
      dh=950;
      uc=0.097;
      uh=0.2700*10^-3;
      hfg=2.26*10^6;
      Tci=50;
      Tco=60;
      cpc=2.03*10^3;
      L=1.72;
      Nprc=795;
      Nprh=1.5;
      q=mc*cpc*(Tco-Tci);
      Thi=100;
      Tho=100;
      kc=0.014;
      kh=0.6818;
      hdi=5555;
      hdo=1500;
      Tlm=Thi-(Tco+Tci)/2;
      mh=q/hfg
      Ao=q/(Uo*Tlm);
      n=Ao/(3.14*D*L)
      vc=mc/(dc*3.14*D^2/4*n);
      Nrec=vc*dc*D/uc;
  if Nrec>2100
      hi=n*kc*0.027*Nrec^0.8*Nprc^(1/3)/D;
  else
      hi=n*kc*1.86*(Nrec*Nprc*D/L)^(1/3)/D;
  end
  ho=0.725*(dh*dh*9.81*hfg*D^3/(n*uh*kh*45))^(1/4)*kh/D;
  Ur=1/(1/ho+1/hi+1/hdo+1/hdi)
  if Ur==Uo
      break
  end
  end
  end

Answer 1

[the cyclist]

Because of floating point error, they are probably not exactly equal. Try something like

tol = 1.e-12;
if abs(Ur-Uo) < tol;
  ...

You might need to adjust the tolerance.

[fff fff]

Thank you. This is what i was look for.