Dim Temp, t, dt, i, k1, k2, k3, k4, k

'forth order runge kutta method to solve d(Temp)/dt = f(Temp)

'initial conditions
'Temp = 25 + 273
Temp = 174.75 + 273
t = 0

'time step
dt = 0.1

'runge kutta integration
For i = 1 To 10000  '4231
   k1 = f(Temp)
   k2 = f(Temp + k1 * dt / 2)
   k3 = f(Temp + k2 * dt / 2)
   k4 = f(Temp + k3 * dt)
   k = (k1 + 2 * k2 + 2 * k3 + k4) / 6
   Temp = Temp + k * dt
   t = t + dt
   
   'If Temp > 150 + 273 Then Exit For
   If Temp < 37 + 273 Then Exit For
Next i

Picture1.Cls
Picture1.Print "i", "t (s)", "Temp (C)"
Picture1.Print i, t, Temp - 273