PETSc.jl - a julia interface to the Portable, Extensible Toolkit for Scientific Computation

PETSc is a widely used scientific computing library that allows you to write software that runs on massively parallel supercomputers.  PETSc is written in C but provides interfaces for Fortran and Python. Here, I present PETSc.jl, which is a Julia interface to the (nearly) full PETSc library.

There are a number of advantages compared to other attempts:

• It can be very easily installed by typing "add PETSc" in the Julia package manager and is distributed with precompiled PETSc binaries and MPI.
• We provide both a high-level and a low-level interface. The low-level interface automatically wraps nearly the full PETSc library with over 3000 functions, whereas the high-level interface gives a more Julia-like experience but is currently limited to part of the library.
• Automatic testing and CI/CD is performed with currently >50’000 tests.
• Users can combine features from Julia, the Julia ecosystem, such as automatic differentiation and plotting with PETSc solvers.
• The resulting codes are much more compact than their counterparts in lower-level languages; yet, users still have access to all PETSc features, such as multigrid solvers for DMDA or DMStag grids.
• It allows running code on both a local workstation and on a large HPC system.

In the presentation, I will summarise some of the work done to achieve this and show scalability results of typical codes. I will also compare the timing with native compiled code.