Engineering and Scientific Subroutine Library (ESSL)

For complete documentation see:

• Engineering and Scientific Subroutine Library (ESSL) Documentation

ESSL is a collection of subroutines providing a wide range of mathematical functions for many different scientific and engineering applications. Its primary characteristics are performance, functional capability, and usability.

The ESSL library is not loaded by default. You must link with the ESSL library when you compile your program. An example compile line is

% mpxlf90 -o executable_name mycode.f -lessl

The computational areas covered by ESSL are:

• Linear Algebra Subprograms
• Matrix Operations
• Linear Algebraic Equations
• Eigensystem Analysis
• Fourier Transforms, Convolutions and Correlations, and Related Computations
• Sorting and Searching
• Interpolation
• Numerical Quadrature
• Random Number Generation

ESSL provides three run-time libraries:

• The ESSL Symmetric Multi-Processing (SMP) Library provides thread-safe versions of the ESSL subroutines for use on the SMP processors. In addition, a subset of these subroutines are also multithreaded versions; that is, they support the shared memory parallel processing programming model.
• The ESSL Thread-Safe Library provides thread-safe versions of the ESSL subroutines for use on all RS/6000 processors. You may use this library to develop your own multithreaded applications.
• The ESSL POWER Library is tuned for the POWER processors.