BLAS1_D
Basic Linear Algebra Subprograms
Level 1
Double Precision Real Arithmetic

BLAS1_D is a C library which implements the Level 1 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 1 BLAS are primarily for use in vector operations. In certain cases, they may also be used to operate on the rows or columns of a two-dimensional array.

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

BLAS1_D is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.

Related Data and Programs:

BLAS0, a C library which contains auxilliary functions for the Basic Linear Algebra Subprograms (BLAS).

BLAS1_C, a C library which contains basic linear algebra routines for vector-vector operations, using single precision complex arithmetic.

BLAS1_S, a C library which contains basic linear algebra routines for vector-vector operations, using single precision real arithmetic.

BLAS1_Z, a C library which contains basic linear algebra routines for vector-vector operations, using double precision complex arithmetic.

BLAS2, a C library which contains basic linear algebra subprograms (BLAS) for matrix-vector operations;

BLAS3, a C library which contains basic linear algebra subprograms (BLAS) for matrix-matrix operations;

CLAPACK, C programs which illustrate the use of the CLAPACK library, a translation of the FORTRAN77 BLAS and LAPACK linear algebra libraries, including single and double precision, real and complex arithmetic.

LINPACK, a C library which solves linear systems using double precision real arithmetic;

SUPER_BLAS, a C library which implements some of the Basic Linear Algebra Subprograms for fast execution.

SVD_DEMO, a C program which demonstrates the Singular Value Decomposition (SVD) for a simple example.

Author:

Original FORTRAN77 version by Charles Lawson, Richard Hanson, David Kincaid, Fred Krogh. C version by John Burkardt.

Reference:

1. Thomas Coleman, Charles vanLoan,
   Handbook for Matrix Computations,
   SIAM, 1988,
   ISBN13: 978-0-898712-27-8,
   LC: QA188.C65.
2. Jack Dongarra, Jim Bunch, Cleve Moler, Pete Stewart,
   LINPACK User's Guide,
   SIAM, 1979,
   ISBN13: 978-0-898711-72-1,
   LC: QA214.L56.
3. 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:

• blas1_d.c, the source code.
• blas1_d.h, the include file.

Examples and Tests:

• blas1_d_test.c, the calling program.
• blas1_d_test.txt the output file.

List of Routines:

• DASUM takes the sum of the absolute values of a double vector.
• DAXPY computes double constant times a vector plus a vector.
• DCOPY copies a double vector X to a vector Y.
• DDOT forms the dot product of two double vectors.
• DMACH computes machine parameters of double arithmetic.
• DNRM2 returns the euclidean norm of a double vector.
• DROT applies a double plane rotation.
• DROTG constructs a double Givens plane rotation.
• DSCAL scales a double vector by a constant.
• DSWAP interchanges two double vectors.
• I4_MAX returns the maximum of two integers.
• I4_MIN returns the smaller of two integers.
• IDAMAX finds the index of the double vector element of maximum absolute value.
• LSAME returns TRUE if CA is the same letter as CB regardless of case.
• R9_ABS returns the absolute value of a double.
• R8_MAX returns the maximum of two doubles.
• R8_SIGN returns the sign of a double.
• XERBLA is an error handler for the LAPACK routines.

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