Owl is a dedicated system for scientific and engineering computing in the
functional programming language OCaml.
This software is currently maintained by Komposio, a
Helsinki-based software consulting company.
Visit the project website at ocaml.xyz
You can enable optional features by setting the following variables to
OWL_ENABLE_EXPMODE=1: turn on experiment features like
OWL_ENABLE_DEVMODE=1: turn on all the warnings in development
OWL_ENABLE_OPENMP=1: turn on OpenMP support in core module and
the automatic parameter tuning (AEOS)
OWL_CFLAGSallows to change the default flags passed to the C targets,
it defaults to
OWL_CFLAGS="-g -O3 -Ofast -march=native -mfpmath=sse -funroll-loops -ffast-math -DSFMT_MEXP=19937 -msse2 -fno-strict-aliasing -Wno-tautological-constant-out-of-range-compare"`
OWL_AEOS_CFLAGSallows to change the default flags passed to the C targets
when compiling AEOS. It defaults to
OWL_AEOS_CFLAGS="-g -O3 -Ofast -march=native -funroll-loops -ffast-math -DSFMT_MEXP=19937 -fno-strict-aliasing"
-llapackeflag in the
linking options. This is useful when you have lapacke installed on
If you are not using
opam, you should run
make clean before recompiling
the library after having changed any of those environment variables.
For examples of use of this feature, you can refer to the
Docker.ubuntu.arm docker files, or to the snippet in
(which also shows how to use it within
A common source of frustration when installing
owl is the possible appearence of linking errors (see for example https://github.com/owlbarn/owl/issues/450).
This usually happens when installing
owl on ubuntu (where it depends on how openblas is complied and packaged), but could happen in other distributions (see for example https://discuss.ocaml.org/t/owl-undefined-symbols-after-standard-installation/4186/13).
The only way we could solve those issues is to recompile
openblas and install it manually. You can see how we do it by looking at the Docker files in the repository: https://github.com/owlbarn/owl/blob/master/docker/Dockerfile.ubuntu