Numo::OpenBLAS

Numo::OpenBLAS downloads and builds OpenBLAS during installation and uses that as a background library for Numo::Linalg.

Building LAPACK included with OpenBLAS requires Fortran compiler.

macOS:

$ brew install gfortran

Ubuntu:

$ sudo apt-get install gfortran

Add this line to your application's Gemfile:

gem 'numo-openblas'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install numo-openblas

Note: Numo::OpenBLAS downloads and builds OpenBLAS during installation. In many cases, building OpenBLAS takes a lot of time. In addtion, the building OpenBLAS may fail on Apple M1 mac due to linker error:

ld: warning: object file (...) was built for newer macOS version (...) than being linked (...)
...
Undefined symbols for architecture arm64:
  "___chkstk_darwin", referenced from:
  _sgemv_ in libopenblas_vortexp-r0.3.19.a(sgemv.o)
  _sger_ in libopenblas_vortexp-r0.3.19.a(sger.o)
  _cblas_sgemv in libopenblas_vortexp-r0.3.19.a(cblas_sgemv.o)
  _cblas_sger in libopenblas_vortexp-r0.3.19.a(cblas_sger.o)
  _dgemv_ in libopenblas_vortexp-r0.3.19.a(dgemv.o)
  _dger_ in libopenblas_vortexp-r0.3.19.a(dger.o)
  _cblas_dgemv in libopenblas_vortexp-r0.3.19.a(cblas_dgemv.o)
  ...
ld: symbol(s) not found for architecture arm64

In that case, you can install it by giving MACOSX_DEPLOYMENT_TARGET your mac version. If you are using macOS Monterey, the installation command would be:

$ MACOSX_DEPLOYMENT_TARGET=12.0 gem install numo-openblas

Numo::OpenBLAS loads Numo::NArray and Numo::Linalg using OpenBLAS as a background library. You can use Numo::NArray and Numo::Linalg just by loading Numo::OpenBLAS.

require 'numo/openblas'

x = Numo::DFloat.new(5, 2).rand
c = x.transpose.dot(x)
eig_val, eig_vec = Numo::Linalg.eigh(c)

Moreover, some of the build options are defined by constants.

> Numo::OpenBLAS::OPENBLAS_VERSION
=> " OpenBLAS 0.3.10 "
> Numo::OpenBLAS::OPENBLAS_CHAR_CORENAME
=> "HASWELL"
> Numo::OpenBLAS::OPENBLAS_NUM_CORES
=> 8

Bug reports and pull requests are welcome on GitHub at https://github.com/yoshoku/numo-openblas. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the BSD-3-Clause License.