Development/GSL

Description	Content
module load	numlib/gsl
Availability	bwUniCluster_2.0 | BwForCluster_JUSTUS_2
License	GNU General Public License (GPL)
Citing	M. Galassi et al., GNU Scientific Library Reference Manual (3rd Ed.), ISBN 0954612078.
Links	Homepage | Documentation
Graphical Interface	No

Description

The GNU Scientific Library (GSL) is a software library for numerical computations in applied mathematics and science. GSL is written in C, but bindings exist for other programming languages as well. The library provides a wide range of mathematical routines such as random number generators, special functions and least-squares fitting. There are over 1000 functions in total with an extensive test suite.

The complete range of subject areas covered by the library includes
• Complex Numbers • Roots of Polynomials • Special Functions • Vectors and Matrices • Permutations • Sorting • BLAS Support • Linear Algebra • Eigensystems • Fast Fourier Transforms • Quadrature • Random Numbers • Quasi-Random Sequences • Random Distributions • Statistics • Histograms • N-Tuples • Monte Carlo Integration • Simulated Annealing • Differential Equations • Interpolation • Numerical Differentiation • Chebyshev Approximation • Series Acceleration • Discrete Hankel Transforms • Root-Finding • Minimization • Least-Squares Fitting • Physical Constants • IEEE Floating-Point • Discrete Wavelet Transforms • Basis splines • Running Statistics • Sparse Matrices and Linear Algebra

Availability

GSL is available on selected bwHPC-Clusters. A complete list of versions currently installed on the bwHPC-Clusters can be obtained from the Cluster Information System (CIS).

In order to check which versions of GSL are installed on the compute cluster, run the following command:

$ module avail numlib/gsl

Documentation

Online

• Online-Documentation

Local

• info gsl
• man gsl
• man gsl-config

Usage

Loading the module

You can load the default version of GSL with the following command:

$ module load numlib/gsl

The module will try to load all modules it needs to function (e.g., compiler, mpi, ...). If loading the module fails, check if you have already loaded one of those modules, but not in the version required by GSL.

If you wish to load another (older) version of GSL, you can do so using

$ module load numlib/gsl/<version>

with <version> specifying the desired version.

GSL-Specific Environments

To see a list of all GSL environments set by the 'module load'-command use 'env | grep GSL'.
Or use the command 'module show numlib/gsl'.

$ module show numlib/gsl
-----------------------------------------------------------------
/opt/bwhpc/common/modulefiles/numlib/gsl/1.16-intel-13.1:
GSL_VERSION = 1.16 
GSL_HOME = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1 
GSL_BIN_DIR = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/bin 
GSL_INC_DIR = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/include 
GSL_LIB_DIR = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/lib 
GSL_STA_DIR = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/lib 
GSL_SHA_DIR = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/lib 
GSL_MAN_DIR = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/share/man 
GSL_INF_DIR = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/share/info 
GSL_DOC_DIR = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/share/doc 
GSL_EXA_DIR = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/share/doc/examples 
GSL_WWW http://www.gnu.org/software/gsl/ 
PATH = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/bin:$PATH
MANPATH = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/share/man:$MANPATH
INFOPATH = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/share/info:$INFOPATH
LD_LIBRARY_PATH = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/lib:$LD_LIBRARY_PATH
INCLUDE = /opt/bwhpc/common/numlib/gsl/1.16-intel-13.1/include:$INCLUDE
[...] 

How To Use the Library

Includes

Your source code should contain preprocessor include statements with a gsl/ prefix, such as

#include <gsl/gsl_math.h>

Compile

A typical compilation command for a source file example.c with the Intel C compiler icc is

 $ icc -Wall -I$GSL_INC_DIR  -c example.c 

The $GSL_INC_DIR environment variable points to location of the include path for the gsl header files.

Link

The following command can be used to link the application with the gsl libraries.

 $ icc -L$GSL_LIB_DIR -o example example.o -lgsl -lgslcblas -lm 

The $GSL_LIB_DIR environment variable points to the location of the gsl libraries.
Also make sure to have the GSL-module loaded before running applications build with this library.

Example C-Source Code

Create source code file 'intro.c'

#include <stdio.h>
#include <gsl/gsl_sf_bessel.h>

int main (void)
{
  double x = 5.0;
  double y = gsl_sf_bessel_J0 (x);
  printf ("J0(%g) = %.18e\n", x, y);
  return 0;
}

Bessel-Functions and more

Compile and Link

Load the GSL module for the Intel compiler, compile, link and run the program

$ module load numlib/gsl/1.16-intel-13.1
Loading module dependency 'compiler/intel/13.1'.
$ icc -Wall -I$GSL_INC_DIR  -c intro.c
$ icc -L$GSL_LIB_DIR -o intro intro.o -lgsl -lgslcblas -lm
$ ./intro
J0(5) = -1.775967713143382642e-01