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This floating point variable has to be set to an elementary time interval. In order not to degrade the code performance, DT should be set to a value much larger than the time step allowed by the CFL criterion. The code will split the interval [t,t+DT] in as many time steps as necessary so as to fulfill the CFL criterion (the latter is evaluated at every time step, unless the -c flag is set). The last time step will be performed so that the new date is exactly t+DT (the corresponding time increment can therefore be much smaller than what is allowed by the CFL criterion, for this last time step). A full output is performed every Ninterm*DT, and the total time over which a simulation is run is Ntot*DT. A line is added in the torque files tqwk[i].dat every DT, as well as in the planet file bigplanet[i].dat and orbit[i].dat (where i is the planet number), so DT can be considered as the time interval sampling of all diagnostic files (see also the format of these output files).
At runtime, a dot is sent to the standard output for every elementary hydrodynamic time step performed. A carriage return is sent every time a time interval of length DT has been completed.

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