NAG Math Library

The Numerical Algorithms Group (NAG) is a company based in England, with a U.S. office in Illinois. The NAG library is a comprehensive math library that is usually considered the British analogue of IMSL. The functionality is comparable to that of IMSL. The version on Bassi is double precision.

NOTE: Both 32-bit and 64-bit address space NAG libraries are available on the Bassi.

How to use

On Bassi

% module load nag 
% xlf_r -q64  $NAG ... 
or
% module load nag_32 
% xlf_r  -q32 $NAG ... 

On Opteron Linux cluster (Jacquard)

% module load nag 
% pathf90  ... $NAG  

Example Programs

NAG example programs can be accessed by the command nagexample. For example,

% nagexample c02aff

will copy the source code of the specified example program and its data into the files c02affe.f and c02affe.d in the current directory and then compile, link, and execute the example and write its results to stdout. Further usage details may be obtained by using the command nagexample without arguments.

Documentation

For NERSC implementation-specific see Users' Notes (32BIT , 64BIT ).

For NAG on-line documentation in HTML/PDF format, see the NAG website, and make use of the NAG's search tools for keywords or routine names, or use their Site Map.

NOTE: As of NAG Mark 19, on-line documentation naghelp, is no longer available.

Background

The NAG Fortran Library is a comprehensive collection of Fortran 77 routines for the solution of numerical and statistical problems. The word routine is used to denote subroutine or function.

The Library is divided into chapters, each devoted to a branch of numerical analysis or statistics. Each chapter has a three-character name and a title, e.g.

  D01 - Quadrature

Note:NAG software is classified in accordance with the GAMS Classification system.

All documented routines in the Library have six-character names, beginning with the characters of the chapter name, e.g.

  D01AJF

Note that the second and third characters are digits, not letters; e.g. 0 is the digit zero, not the letter O. The last letter of each routine name always appears as F in the commercial documentation, but it appears as E in single-precision versions.

Periodically a new Mark (Version) of the NAG Fortran Library is released: new routines are added, corrections or improvements are made to existing routines; occasionally routines are withdrawn if they have been superseded by improved routines. See withdrawn routines

Single Precision Naming of Routines

To ensure a single precision version is completely distinct from any double precision version also available, all single precision routine names have been modified by changing the sixth character from F to E. Thus, for example: A02AAF was changed to A02AAE.

Some routines in the Library require users to specify particular auxiliary routines. The names of auxiliary routines have also been modified by interchanging the first three and the last three characters, e.g. C02AFZ has been changed to AFZC02.