Install OpenBLAS and add it to the path

.bashrc

### Lines to add to .bashrc
# for the OpenBLAS library
export LD_LIBRARY_PATH=/path/to/OpenBLAS:$LD_LIBRARY_PATH
export BLAS=/path/to/libopenblas.a
export ATLAS=/path/to/libopenblas.a

install-openblas.sh

# download the OpenBLAS source
git clone https://github.com/xianyi/OpenBLAS
    
# compile the library
cd OpenBLAS && make FC=gfortran

what is the "/path/to/" means and how should I define it. How "/path/to/" related to OpenBLAS directory?

@rahmahi: /path/to just means the absolute path the respective libraries and folders. So, for example, something like: export BLAS=/home/bmmalone/local/lib/libopenblas.a

Hello,
I am using ubuntu 18.0.4, if I installed Openblas using sudo apt-get install libopenblas-dev command. Does that mean it is not necessary to install again Openblas using git clone https://github.com/xianyi/OpenBLAS ? If not, what's the difference between those two packages.

Hey @nagarjunvinukonda: The versions are probably about the same; sometimes, the versions in the apt-get repositories are a little behind the version in the main repository.

The main difference is that using sudo requires, well, sudo/root access, while installing via the script can be done without root access. Thus, if you are in a computing environment where you don't have root access, sudo isn't possible.

It's also a little easier if you need to install multiple versions of openblas for some reason (since the location of the versions is controlled explicitly, while the location of files from apt-get can be difficult to track).