Continue simulation with a new "Number of Timesteps"

[Amirtaha Taebi]

Dear SimVascularers,

After my simulation was done (8000 time steps, time step size: 0.0003), I noticed that I didn't choose enough number of time steps. Actually, I need to run the simulation for at least an extra 9000 time steps to get full 5 cardiac cycles. Since my simulation is computationally expensive, I am wondering if I can continue the simulation from what I already have.

I see that we can select the "Starting Step Number" before we run the simulation. Should I "Create Data Files for Simulation" with the new "Number of Timesteps" (let's say 17000), and then run the simulation from timestep 8000? Or I don't need to "Create Data Files for Simulation" again? Is there anything else that I need to pay attention to?


Thank you very much,
Amirtaha

[Amirtaha Taebi]

Here is what I finally ended up to solve this for anyone who might have the same question in future.

1. Used the "Last step to restart.x.0" to create restart file from the last step of previous simulation.
2. Renamed restart.8000.0 file to restart.0.1
3. Created a new simulation with the additional number of time steps that I need. Created simulation files.
4. Replaced the restart.0.1 file in the simulation folder with the restart.0.1 created in step 2
5. Ran the simulation from timestep 0

Dear SimVascular developers, please let me know if this is the right procedure.
Thanks,
Amirtaha

[Hongzhi Lan]

Hi Amirtaha,

You can refer to http://simvascular.github.io/docsFlowSo ... runningjob

Specifically, an alternative way to continue a previous simulation is (in your case):

Solver Parameters
Number of Timesteps: 9000

Create Files and Run Simulation
Number of Processes: use the same number of processes as the previous simulation
Starting Step Number: keep empty ( in your case, the simulation will start from where you ended last time, step 8000)
Click the button "Run Job"

Just follow the steps above and keep other parameters same as the previous simulation.
No other extra steps. No "Create Data Files for Simulation" .

When the simulation done, you'll get totally 8000+9000=17000 steps.

Hongzhi

[Amirtaha Taebi]

Dear Hongzhi,
Thank you very much for the clarification and procedure. I will follow these steps.

Could you also please confirm if the procedure that I explained in my previous message was correct as well or not.

Thanks,
Amirtaha

[Hongzhi Lan]

Hi Amirtaha,

The way you mentioned before should work!

Hongzhi

[Amirtaha Taebi]

Hi Hongzhi,

Thanks. I followed the way that you suggested. The new simulation stopped at time step 16000 while the simulation is not 100% completed yet. So I suspect we might needed to create files for simulation again.
This second simulation started from time step number 8000 and ended at 16000. How can I make sure that the second simulation is really the continuation of the first simulation? I mean we did not set anywhere the initial condition to the last time step of the previous simulation.

Thanks,
Amirtaha