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Frequently Asked Questions (FAQ)


Table of Contents

General
1.1 What is this FAQ for?
1.2 Where can I get a copy of this FAQ?
1.3 Where should I send comments and corrections for this FAQ?
1.4 What is the Netlib Question and Answer Forum?

Netlib
2.1) What is Netlib?
2.2) How do I retrieve software or documents from Netlib?
2.3) Are there restrictions on the use of software retrieved from Netlib?
2.4) How do I submit software or documents to Netlib?
2.5) Where are the Netlib mirror sites?
2.6) Which sites use the Netlib email server to distribute other types of software?
2.7) Where can I find more information about Netlib?
2.8) What is Xnetlib?
2.9) How do I find a particular routine?
2.10) How do I find software to solve a particular problem?
2.11) I can't get a program to work. What should I do?
2.12) Where can I find documentation for a particular program?
2.13) What is dependency checking and how does it work?
2.14) I requested some software but didn't get all the routines I needed. Why?
2.15) What and where are the BLAS?
2.16) Why don't I get needed BLAS automatically when I select LAPACK routines?
2.17) What and where are r1mach, d1mach, and i1mach?
2.18) How can I unpack foo.tar.z?
2.19) How can I unpack foo.tgz?
2.20) Does Netlib offer technical support?
2.21) Can I download all/lots of the Netlib repository?
2.22) How can I become a Netlib site?
2.23) How can I use the Netlib program to run my own repository?
2.24) What if I have other questions about Netlib?

1) General


1.1) What is this FAQ for?
To provide basic introductory information and answers to frequently asked questions about Netlib.

1.2) Where can I get a copy of this FAQ?
The most recent version of this FAQ can be retrieved from

http://www.netlib.org/misc/faq.html

or

ftp://ftp.netlib.org/misc/faq

1.3) Where should I send comments and corrections for this FAQ?
Send email to netlib_maintainers@netlib.org

1.4) What is the Netlib Question and Answer Forum? Netlib Question and Answer Forum is bulletin board moderated by Netlib group. Feel free to post, answer, and discuss questions of other people.


2) Netlib

2.1) What is Netlib?
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.

2.2) How do I retrieve software or documents from Netlib?
Mechanisms include the World Wide Web (WWW), email, ftp, gopher, xnetlib:

2.3) Are there restrictions on the use of software retrieved from Netlib?
Most netlib software packages have no restrictions on their use but we recommend you check with the authors to be sure. Checking with the authors is a nice courtesy anyway since many authors like to know how their codes are being used.

2.4) How do I submit software or documents to Netlib?
Direct inqueries to netlib_maintainers@netlib.org

2.5) Where are the official Netlib mirror sites?
See

http://www.netlib.org/bib/mirrors.html
for the list of official Netlib mirror sites.

2.6) Which sites use the Netlib email server to distribute other types of software?
A collection of statistical software is available from

statlib@temper.stat.cmu.edu
The TeX User Group distributes TeX-related software from
tuglib@math.utah.edu
The symbolic algebra system REDUCE is supported by
reduce-netlib@rand.org
Parallel software and information about parallel processing is available from
parlib@hubcap.clemson.edu
Dozens of other specialized sites also use the processor which can be found in /netlib/misc/netlib.

2.7) Where can I find more information about Netlib?
A collection of working notes related to the Netlib repository is available at :

http://www.netlib.org/srwn/

2.8) What is Xnetlib?
Xnetlib is an X Window System application that provides interactive file access and database query processing from multiple servers through TCP/IP connections. Xnetlib currently provides access to the Netlib software and document repository, and the NA-NET Whitepages Database.

The last release of Xnetlib was version 1.3. Since its release, most of its capabilities have been superceded by World Wide Web browsers like Mosiac or Netscape. Since most of the efforts at Netlib are presently geared more towards the World Wide Web, we recommend using a WWW browser.

2.9) How do I find a particular routine?
The most powerful search capabilities in Netlib are provided through the interface at

http://www.netlib.org/utk/misc/netlib_query.html
One way to search for a particular routine, say "foo", would be to submit the search query "file=foo".

The Netlib email interface has a similar capability. Send the email message "find foo" to netlib@netlib.org or another Netlib site.

2.10) How do I find software to solve a particular problem?
One way is to identify appropriate keywords and then use the Web search interface at

http://www.netlib.org/utk/misc/netlib_query.html
or the "find" feature of the Netlib email interface and send the email message to netlib@netlib.org or another Netlib site.

The GAMS mathematical software classification system enables users to find suitable software by browsing the problem hierarchy. You can use GAMS from the search interface or by linking to

http://www.netlib.org/bib/gams.html
or
http://gams.nist.gov/
Send the message "send gams from bib" to netlib@netlib.org to retrieve the GAMS classification by email.

Another way is to browse the Netlib libraries list and to identify libraries appropriate to your problem. You can then browse the contents of these individual libraries. Using a Web interface, look at

http://www.netlib.org/liblist.html
Using an email interface, send the message "send index" to netlib@netlib.org or another Netlib site to receive a descriptive list of the libraries in Netlib. Send the message "send index for foo" to receive the index for library foo.

2.11) I can't get a program to work. What should I do?
Technical questions about the proper use of a software package should be directed to the authors of that package.

2.12) Where can I find documentation for a particular program?
Documentation for a particular software package generally comes with the software bundle or resides in the same directory as the software. Note that much of the software in Netlib is self-documenting - the comments in the code provide all the documentation you need.

2.13) What is dependency checking and how does it work?
Dependency checking is Netlib's mechanism for sending routines called by those routines a user has explicitly selected. A single request for the highest level routine should therefore get all the routines a user needs.

Dependencies are generated from a script that looks at the load map for each software package. A manually edited file tells Netlib which directories to scan for dependent routines.

2.14) I requested some software but didn't get all the routines I needed. Why?
Send email to netlib_maintainers@netlib.org describing the behavior.

2.15) What and where are the BLAS?
The BLAS (Basic Linear Algebra Subprograms) are high quality "building block" routines for performing basic vector and matrix operations. Level 1 BLAS do vector-vector operations, Level 2 BLAS do matrix-vector operations, and Level 3 BLAS do matrix-matrix operations. Because the BLAS are efficient, portable, and widely available, they're commonly used in the development of high quality linear algebra software, LINPACK and LAPACK for example.

The BLAS are located in the blas directory of Netlib.

2.16) Why don't I get needed BLAS automatically when I select LAPACK routines?
LAPACK is designed especially for high-performance computing so the LAPACK group prefers that users use tuned vendor-supplied BLAS whenever possible.

2.17) What and where are r1mach, d1mach, and i1mach?
These routines are used to specify machine-dependent parameters such as your machine's precision. They're used by several packages, most commonly to ensure that tolerances used in the software is reasonable for a particular machine.

The easiest to use versions of the routines r1mach, d1mach, and i1mach are located in the blas directory of Netlib. These versions of r1mach and d1mach attempt to determine machine characteristics automatically.

The original versions of r1mach, d1mach, and i1mach, in the slatec/src directory, require a user to scan their source and to uncomment the statements specifying the constants for his particular machine. Constants for some architectures are not explicitly identified in the comments of r1mach, d1mach, and i1mach. For those architectures conforming to the IEEE floating-point standard, and most newer ones do, you can locate and uncomment the IEEE-conforming constants in the routines.

2.18) How can I unpack foo.tar.z?

   mv foo.tar.z foo.tar.Z
   uncompress foo.tar.Z
   tar xvf foo.tar

2.19) How can I unpack foo.tgz?

   gunzip foo.tgz
   tar xvf foo.tar
For Windows and Mac, commercial tools are available from www.winzip.com and www.stuffit.com.

2.20) Does Netlib offer technical support?
No. Technical questions should be directed to the authors of the software package.

2.21) Can I download all/lots of the Netlib repository?
Yes. Note however that downloading software that isn't going to be used right away tends to waste time and space. When you're finally ready to use it you may end up downloading it again from Netlib just be sure you have the latest version. For this same reason, downloading all of Netlib's software and storing it someplace is not the best way to build a local software repository.

2.22) How can I become a Netlib mirror site?
First check the list of mirror sites (Question 2.5) to see if an existing Netlib site could meet your needs. Then read the policy on becoming a Netlib mirror site at

http://www.netlib.org/bib/mirrors.html
.
Direct inquiries to
maintainers.
See the contents of the directory /netlib/crc for technical information on mirroring.

2.23) How can I use the Netlib program to run my own repository?
You can retrieve the source code for the Netlib email system from the "netlib" directory of the Netlib repository. For example, to retrieve the Netlib program by email send the message

   send netlib from netlib
to
netlib@netlib.org.

2.24) What if I have other questions about Netlib?
The srwn directory contains papers that may be of assistance. Point your Web browser to

http://www.netlib.org/srwn/
Send your questions to
netlib_maintainers at netlib.org