High-performance multi-user code development with Google Code

1. High-performance multi-user code development with Google Code  Current status  (...just google for Pencil Code)

2. Pencilcode • Started in Sept. 2001 with Wolfgang Dobler • High order (6th order in space, 3rd order in time) • Cache & memory efficient • MPI, can run PacxMPI (across countries!) • Maintained/developed by ~40 people (SVN) • Automatic validation (over night or any time) • 0.0013 ms/pt/step at 10243 , 2048 procs • http://pencil-code.googlecode.com • Isotropic turbulence • MHD, passive scl, CR • Stratified layers • Convection, radiation • Shearing box • MRI, dust, interstellar • Self-gravity • Sphere embedded in box • Fully convective stars • geodynamo • Other applications • Chemistry, combustion • Spherical coordinates

3. Scaling properties Wlad Lyra on Kraken Babkovskaia et al (2011)

4. PencilCode • Started in Sept. 2001 with Wolfgang Dobler • High order (6th order in space, 3rd order in time) • Cache & memory efficient • MPI, can run PacxMPI (across countries!) • Maintained/developed by ~40 people (SVN) • Automatic validation (over night or any time) • Max resolution so far 10243 , 4096 procs • http://pencil-code.googlecode.com • Isotropic turbulence • MHD, passive scl, CR • Stratified layers • Convection, radiation • Shearing box • MRI, dust, interstellar • Self-gravity • Sphere embedded in box • Fully convective stars • geodynamo • Other applications • Homochirality • Spherical coordinates

5. Google Code webpage

6. Continuous updates online

7. Automatic validation tests

8. Evolution of code size User meetings: 2005 Copenhagen 2006 Copenhagen 2007 Stockholm 2008 Leiden 2009 Heidelberg 2010 New York 2011 Toulouse 2012 Helsinki

9. Increase in # of auto tests

10. Regularity of check-ins

11. More check-ins since 2010

12. Return to previous rate

17. Tutorial

18. Tutorial pages

19. Olhol

20. Olhoh.net analysis

21. Credit

22. Free licence, but giving credit to research

23. Faster and bigger machines

24. 256 processor run at 10243

25. Hyperviscous, Smagorinsky, normal height of bottleneck increased Haugen & Brandenburg (PRE, astro-ph/0402301) onset of bottleneck at same position Inertial range unaffected by artificial diffusion

26. Online data reduction and visualization non-helically forced turbulence

27. Scalars on periphery of the box

28. MRI turbulenceMRI = magnetorotational instability 2563 w/o hypervisc. t = 600 = 20 orbits 5123 w/o hypervisc. Dt = 60 = 2 orbits

29. Vorticity and Density See poster by Tobi Heinemann on density wave excitation!

30. Intrinsic Calculation Ray direction Transfer equation & parallelization Processors Analytic Solution:

31. Analytic Solution: Communication Ray direction The Transfer Equation & Parallelization Processors

32. Analytic Solution: Intrinsic Calculation Ray direction The Transfer Equation & Parallelization Processors

33. Future developments • Adaptive/multiple mesh • More 3-D online graphics output • Poisson solver for non-Cartesian geometries • Parallel developments with graphics card