Output from while-loop at fixed values

I am running time-dependent simulations with variable time-step size dt in seconds. I have implemented a while-loop that updates the elapsed time t_elapsed as t_elapsed + dt and stops when t_elapsed > t_total where t_total is a predefined number in seconds. Now I want to output the solution (a vector) to a text file at every x seconds, i.e. every 3600 seconds. This problem throws me of my game a bit as dt is now variable. Any help is much appreciated.

Arjan

Answer 1

[dpb]

Either compute the number of timesteps corresponding to your dt and desired frequency if dt is constant and output every N timesteps:

N=Tout/dt;
if mod(iterNo,N)==0
  fprintf(fid,data)
end

or, alternatively, test the time variable modulo Tout is within dt. ismembertol might be of interest here for floating point comparisons.

[Arjan Marelis]

dpb,

thank you. The ismembertol function solves the problem!