Development/GSL: Difference between revisions

From bwHPC Wiki
Jump to navigation Jump to search
Line 91: Line 91:
= Examples =
= Examples =


Consider the following FFTW task.
Consider the following GSL task.


<source lang="c">
<source lang="c">

Revision as of 23:41, 2 June 2021

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:

• 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

A documentation for GSL is available online.

The help page of the GSL module provides more version specific information:

$ module help numlib/gsl

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.

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.

Examples

Consider the following GSL task.

#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;
}

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


Useful links