define_time_step Subroutine

  subroutine define_time_step(params,F)
    !! @note Subroutine that defines or loads from restart file the time
    !! stepping parameters. @endnote
    TYPE(KORC_PARAMS), INTENT(INOUT) :: params
    TYPE(FIELDS), INTENT(INOUT) :: F
    !! Core KORC simulation parameters.

    if (params%restart) then
       call load_time_stepping_params(params)
       
    else if (params%proceed.or.params%reinit) then
       
       call load_prev_time(params)
       
       params%ito = 1_ip

       params%dt = params%dt*(2.0_rp*C_PI*params%cpp%time_r)

       params%t_steps = CEILING((params%simulation_time-params%init_time)/ &
            params%dt,ip)

       params%output_cadence = CEILING(params%snapshot_frequency/params%dt,ip)

       if (params%output_cadence.EQ.0_ip) params%output_cadence = 1_ip

       params%num_snapshots = params%t_steps/params%output_cadence

       if (params%t_steps.gt.params%output_cadence) then
          params%dt=params%snapshot_frequency/float(params%output_cadence)
       endif
       
       params%restart_output_cadence = CEILING(params%restart_overwrite_frequency/ &
            params%dt,ip)


       params%t_skip=min(params%t_steps,params%output_cadence)
       params%t_skip=max(1_ip,params%t_skip)


    else
       params%ito = 1_ip

       params%dt = params%dt*(2.0_rp*C_PI*params%cpp%time_r)

       params%t_steps = CEILING(params%simulation_time/params%dt,ip)
       
       params%output_cadence = CEILING(params%snapshot_frequency/params%dt,ip)

       if (params%output_cadence.EQ.0_ip) params%output_cadence = 1_ip

       params%num_snapshots = params%t_steps/params%output_cadence

       if (params%t_steps.gt.params%output_cadence) then
          params%dt=params%snapshot_frequency/float(params%output_cadence)
       endif

       params%restart_output_cadence = CEILING(params%restart_overwrite_frequency/ &
            params%dt,ip)

       params%t_skip=min(params%t_steps,params%output_cadence)
       params%t_skip=max(1_ip,params%t_skip)

    end if

    !    write(output_unit_write,*) 'dt',params%dt,'t_skip',params%t_skip

    if (params%mpi_params%rank .EQ. 0) then
       write(output_unit_write,'(/,"* * * * * TIME STEPPING PARAMETERS * * * * *")')
       write(output_unit_write,'("Simulation time: ",E17.10," s")') params%simulation_time
       write(output_unit_write,'("Initial time: ",E17.10," s")') params%init_time     
       write(output_unit_write,'("Output frequency: ",E17.10," s")') params%snapshot_frequency
       write(output_unit_write,'("Relativistic gyro-period: ",E17.10)') 2.0_rp*C_PI* &
            params%cpp%time_r
       write(output_unit_write,'("Time step: ",E17.10)') params%dt
       write(output_unit_write,'("Number of time steps: ",I16)') params%t_steps
       write(output_unit_write,'("Starting simulation at time step: ",I16)') params%ito
       write(output_unit_write,'("Output cadence: ",I16)') params%output_cadence
       write(output_unit_write,'("Restart cadence: ",I16)') params%restart_output_cadence
       write(output_unit_write,'("Number of outputs: ",I16)') params%num_snapshots
       write(output_unit_write,'("* * * * * * * * * * * * * * * * * * * * * * *",/)')
    end if
  end subroutine define_time_step