BLAS2
Level 2 Basic Linear Algebra Subprograms

BLAS2 is a FORTRAN90 library, using double precision arithmetic, which implement the Level 2 BLAS, or Basic Linear Algebra Subprograms.

The BLAS are a small core library of linear algebra utilities, which can be highly optimized for various architectures. Software that relies on the BLAS is thus highly portable, and will typically run very efficiently.

The Level 2 BLAS are designed to handle a variety of matrix-vector operations.

Related Data and Programs:

BLAS1 is a FORTRAN90 library which handles vector-vector operations.

BLAS2 is also available in a FORTRAN77 version.

BLAS3 is a FORTRAN90 library which handles matrix-matrix operations.

ESSL, is a FORTRAN90 library which is the IBM Engineering and Scientific Subroutine Library, and includes an implementation of the BLAS2 routines.

LAPACK is a FORTRAN90 library which is a linear algebra package which relies on the BLAS2 routines.

PETSC is a scientific library for use in parallel computation, which includes an implementation of the BLAS2 routines.

Reference:

1. Edward Anderson, Zhaojun Bai, Christian Bischof, Susan Blackford, James Demmel, Jack Dongarra, Jeremy Du Croz, Anne Greenbaum, Sven Hammarling, Alan McKenney, Danny Sorensen,
   LAPACK User's Guide,
   Third Edition,
   SIAM, 1999,
   ISBN: 0898714478,
   LC: QA76.73.F25L36.
2. Thomas Coleman, Charles vanLoan,
   Handbook for Matrix Computations,
   SIAM, 1988,
   ISBN13: 978-0-898712-27-8,
   LC: QA188.C65.
3. Jack Dongarra, Jim Bunch, Cleve Moler, Pete Stewart,
   LINPACK User's Guide,
   SIAM, 1979,
   ISBN13: 978-0-898711-72-1,
   LC: QA214.L56.
4. Charles Lawson, Richard Hanson, David Kincaid, Fred Krogh,
   Algorithm 539: Basic Linear Algebra Subprograms for Fortran Usage,
   ACM Transactions on Mathematical Software,
   Volume 5, Number 3, September 1979, pages 308-323.

Source Code:

• blas2.f90, the vector code;
• blas2.csh, commands to compile the source code;

Examples and Tests:

• blas2_prb.f90, a calling program;
• blas2_prb.csh, commands to compile, link, load and run the calling program;
• blas2_prb_output.txt, the output file.

List of Routines:

• DGBMV SY:=alpha*A*SX+beta*SY, A a band matrix.
• DGEMV SY:=alpha*A*SX+beta*SY, A a rectangular matrix.
• DGER A:=A+alpha*SX*TRANSPOSE(SY), rank 1 update, A a rectangular matrix.
• DMXPY SY:=SY+A*SX
• DSBMV SY:=alpha*A*SX+beta*SY, A a symmetric band matrix.
• DSPMV SY:=alpha*A*SX+beta*SY, A a packed symmetric matrix.
• DSPR A:=A+alpha*SX*TRANSPOSE(SX), A a packed symmetric matrix.
• DSPR2 A:=A+alpha*SX*TRANSPOSE(SY)+alpha*SY*TRANSPOSE(SX), A packed symmetric.
• DSYMV SY:=alpha*A*SX+beta*SY, A a symmetric matrix.
• DSYR A:=A+alpha*SX*TRANSPOSE(SX), A a symmetric matrix.
• DSYR2 A:=A+alpha*SX*TRANSPOSE(SY)+alpha*SY*TRANSPOSE(SX), A a symmetric matrix.
• DTBMV SX:=A*SX, A a triangular band matrix.
• DTBSV SX:=INVERSE(A)*SX, A a triangular band matrix.
• DTPMV SX:=A*SX, A a packed symmetric matrix.
• DTPSV SX:=INVERSE(A)*SX, A a packed symmetric matrix.
• DTRMV SX:=A*SX, A a triangular matrix.
• DTRSV SX:=INVERSE(A)*SX, A a triangular matrix.
• DXMPY SY:=SY+SX*A

You can go up one level to the FORTRAN90 source codes.