There are three mathematical and
statistical libraries available at STScI: the International Mathematics and Statistics Library (IMSL), the Numerical Algorithms Library (NAg), and the Numerical Recipes library.


IMSL is a set of computational subroutines written in FORTRAN. The subroutines are separated into three groups of libraries known as MATH/LIBRARY, STAT/LIBRARY, and SFUN/LIBRARY.

The MATH/LIBRARY contains 426 routines, separated by function into groups called chapters, for example, routines for solving linear systems are grouped into chapter 1, routines for solving differential equations are grouped into chapter 5, etc.

Statistical analysis routines are located in the STAT/LIBRARY, which is divided into 20 chapters.

The SFUN/LIBRARY contains special functions. It is not divided into chapters, but rather into 12 sections.

A complete set of documentation is available in the Science Software Support Office. The documents include an alphabetical list of all routines and a keyword index. Online help can be found under the topic math_libraries. Users who need additional help using IMSL subroutines should contact the Science Software Support Office.


NAg is a mathematical library written in FORTRAN. It provides a set of algorithms for solving numerical problems, with various algorithms organized into chapters, each of which represent a particular class of problem.

The NAg library is described in a set of manuals that are available in the Science Software Support Office. Each routine is described in detail as to the inputs, outputs, and the meaning of error flags. A sample program listing for each routine allows you to verify that you are using the routine properly. Online help is also available by typing the following command (note that the usual VMS help facility is not used for NAg):


Numerical Recipes

The Numerical Recipes library contains FORTRAN routines for the algorithms described in the classic book Numerical Recipes: The Art of Scientific Computing, by William Press, Brian Flannery, Saul Teukolsky, and William Vetterling. The routines in this library contain source code and must be linked by the user; this allows the user to modify the code. Routines are available on the Science Cluster in the directory SYS$LOCAL:[NUMREC.FOR].

Numerical Recipes

Generated with CERN WebMaker