Working with BLAS library

To install the BLAS and LAPACK library, you can try:

sudo apt-get install libblas-dev liblapack-dev

This will install both BLAS and LAPACK.

Also you should understand that LAPACK uses BLAS libraries in the backend.

Here is the main page of BLAS.

The BLAS (Basic Linear Algebra Subprograms) are routines that provide standard building blocks for performing basic vector and matrix operations. 

• Level 1 BLAS perform scalar, vector and vector-vector operations
• Level 2 BLAS perform matrix-vector operations
• Level 3 BLAS perform matrix-matrix operations. 

Because the BLAS are efficient, portable, and widely available, they are commonly used in the development of high quality linear algebra software, LAPACK for example.





Now, 
How to know whether BLAS library is installed or not?
OR
How to find the location of BLAS library in linux?

type (on the terminal):

locate libblas.so 

This will return the locaiton as follow if BLAS is installed.

/home/username/libblas.so
/home/username/../../../lib/libblas.so
/usr/lib64/libblas.so.3

(for many computational codes (PySCF, etc), BLAS libraries are essential).