3-3  FINDING USEFUL ROUTINES 
 ****************************

 Writing a good procedure may be a time consuming task, and require
 a lot of expertise. It may require a study of the algorithms involved, 
 taking into consideration numerical and programming issues and then 
 programming and careful debugging. 

 Using procedures written by other people saves time and usually can 
 improve your code. However you have to excercize some caution, it may 
 make your programs non-redistributable, also some sources may contain 
 code that is of low-quality from the numerical analytic point of view. 


 Netlib
 ------
 A very large collection of good routines and information by various 
 authors. A quick reference index can be found in appendix E.

 From the Netlib FAQ:

   The Netlib repository contains freely available software, documents,
   and databases of interest to the numerical, scientific computing, and
   other communities. 

   The repository is maintained by AT&T Bell Laboratories, the University 
   of Tennessee and Oak Ridge National Laboratory, and by colleagues 
   world-wide. The collection is replicated at several sites around the 
   world, automatically synchronized, to provide reliable and network 
   efficient service to the global community.
   

  Netlib mirror site     URL
  -------------------    ----------------------------------------------------
  Tennessee, USA         http://www.netlib.org/
  New Jersey, USA        http://netlib.bell-labs.com/netlib/master/readme.html
  Bergen, Norway         http://www.netlib.no/netlib/master/readme.html
  Hensa, Kent, UK        http://www.hensa.ac.uk/ftp/mirrors/netlib/master
  ZIB, Germany           ftp://ftp.zib.de/netlib/
  NCHC, Taiwan           ftp://ftp.nchc.gov.tw/netlib/
  Japan                  http://phase.etl.go.jp/netlib/


  Access method            Directions
  --------------------     ------------------------------------------------
  World Wide Web (WWW)     URL:  http://www.netlib.org/
  email                    for a contents summary and instructions
                           Send the message:  send index
                           to:                netlib@netlib.org
  Anonymous ftp to:        ftp.netlib.org
  gopher                   Point your gopher browser to:  gopher.netlib.org
  xnetlib                  Not recommended
  cd-rom                   Netlib (other than toms) is available on CD-ROM 



 NIST
 ----


 Statlib
 -------


 NCAR
 ----


 NUMERICAL RECIPES
 -----------------
 A library of routines performing most basic numerical tasks, harshly 
 criticized for the quality of the algorithms and numerics, but is 
 cheap and convenient:

        Linear Algebraic System / Interpolation /
        Integration / Approximation / Special Functions /
        Random Numbers / Sorting / Root Finding /
        Minimization / Eigensystems /FFT and applications /
        Statistics / Data Modeling / ODE's / ...                

 Theory and description of the routines can be found in the 
 book:

        NUMERICAL RECIPES in FORTRAN
        The art of scientific computing
        Second edition
        William H. Press / Saul A. Teukolsky
        William T. Vetterling / Brian P. Plannery
        Cambridge University Press
        ISBN 0-521-43064-X

 The routines themselves are distributed in an archived
 form on a PC or MAC diskette. An examples book is also
 available.


 Numerical Algorithms Group (NAG)
 --------------------------------
 A commercial routine library, you link it with your 
 compiled program.


 Visual Numerics (formerly IMSL)
 -------------------------------
 A commercial routine library, you link it with your 
 compiled program.


 MATLAB
 ------
 Matlab is one of many interactive packages, some of them free
 (see the Numerical Analysis FAQ).

 Remember that such interactive packages may run up to 100 times 
 slower than compiled code (ref: Mathlab News and Notes), this 
 figure may be even higher when compared with good Fortran code.