NAG C Library, Mark 6

CLIB606DA

IBM RISC System/6000

Users' Note



Contents


1. Introduction

This document is essential reading for every user of the NAG C Library Implementation specified in the title. It provides implementation-specific detail that augments the information provided in the NAG C Library Manual. Wherever that manual refer to the "Users' Note for your implementation", you should consult this note.

NAG recommends that you read the following minimum reference material before calling any library function:

(a) Essential Introduction
(b) Chapter Introduction
(c) Function Document
(d) Implementation-specific Users' Note

Items (a), (b) and (c) are included in the NAG C Library Manual; item (d) is this document which is provided in HTML form.

2. Availability of Functions

All functions listed in the chapter contents documents of the NAG C Library Manual, Mark 6 are available in this implementation. At Mark 6, 58 new primary ("user-callable") functions have been introduced. Please consult the Mark 6 News document in the C Library Manual for lists of these functions and for a list of functions scheduled for withdrawal at future Marks. Your suggestions for new algorithms for future releases of the Library are welcomed (see Section 7).

3. General Information

3.1. Accessing the Library

Assuming that the libraries libnagc.a, libnagc_sh.a, libnagc_ts.a and libnagc_ts_sh.a have been installed in a directory in the search path of the linker, such as /usr/lib, and that the NAG include files have been moved to /usr/include, then you may link to the non-shareable, non-thread-safe version of the NAG C Library in the following manner: 

xlc driver.c -lnagc -lm
where driver.c is your application program.

You may link to the shareable non-thread-safe form of the NAG C Library in the following manner: 

xlc driver.c -lnagc_sh -lm
To successfully use the thread-safe versions of the libraries, you must also link to the IBM POSIX thread library in the following manner: 
xlc_r driver.c -lnagc_ts -lpthreads -lm
for the non-shareable thread-safe version of the library, and 
xlc_r driver.c -lnagc_sh_ts -lpthreads -lm
for the shareable thread-safe version of the library. Note that, for the thread-safe libraries libnagc_ts.a and libnagc_ts_sh.a, the use of the xlc_r variant of the XLC compiler is advisable. Its use is, in fact, mandatory for any program linking to the NAG C Library routine g05cact.c in either of the thread-safe libraries. If xlc is used instead of xlc_r, a segmentation fault leading to a core dump error may occur.

3.2. Example Programs

The example programs are most easily accessed by the command nagexample, which will provide you with a copy of an example program (and its data, if any), compile the program and link it with the library (showing you the compile command so that you can recompile your own version of the program). Finally, the executable program will be run, presenting its output to stdout. The example program concerned is specified by the argument to nagexample, which should be the (short) name of a NAG C Library function, e.g. 
nagexample c06eac
will copy the example program and its data into the files c06eace.c and c06eafe.d in the current directory and process them to produce the example program results.

3.3. User Documentation

The following machine-readable information files are provided in the doc directory:

A full on-line version of the NAG C Manual is supplied in the form of Portable Document (PDF) files. You will need to check how this version has been made available at your site.

4. Function-specific Information

e04mfc, e04nfc (for all implementations)

A new optional parameter 'optim_tol' has been introduced to allow users a further means of controlling the optimization process.

e04unc (for all implementations)

A member 'needf' has been added to the comm structure to allow users to provide only one component of fi(x) of the objective function in objfun (instead of having to provide all components systematically). This can significantly reduce the computation time when checking and approximating derivatives.

Note that users are not required to modify their existing programs if these changes are not relevant to them.

Any further information which applies to one or more functions in this implementation is listed below, chapter by chapter.

(a) s10 - s21

Functions in this chapter will give error messages if called with illegal or unsafe arguments. General details are given in the NAG C Library Manual, but parameter limits which are implementation-specific are given below: 
s10aac  E(1)      = 18.500
s10abc  fail.code = NE_REAL_ARG_GT if X > 708.0
s10acc  fail.code = NE_REAL_ARG_GT if X > 708.0

s13aac  X(hi)     = 708.3
s13acc  X(hi)     = 1.0e+16
s13adc  X(hi)     = 1.0e+17

s14aac  fail.code = NE_REAL_ARG_GT if X > 170.
        fail.code = NE_REAL_ARG_LT if X < -170.
        fail.code = NE_REAL_ARG_TOO_SMALL if ABS(X) < 2.23e-308
s14abc  fail.code = NE_REAL_ARG_GT if X > 2.55e+305

s17acc  fail.code = NE_REAL_ARG_GT if X > 1.0e+16
s17adc  fail.code = NE_REAL_ARG_GT if X > 1.0e+16
        fail.code = NE_REAL_ARG_TOO_SMALL if X <= 2.23e-308
s17aec  fail.code = NE_REAL_ARG_GT if ABS(X) > 1.0e+16
s17afc  fail.code = NE_REAL_ARG_GT if ABS(X) > 1.0e+16
s17agc  fail.code = NE_REAL_ARG_GT if X > 103.8
        fail.code = NE_REAL_ARG_LT if X < -5.6e+10
s17ahc  fail.code = NE_REAL_ARG_GT if X > 104.1
        fail.code = NE_REAL_ARG_LT if X < -5.6e+10
s17ajc  fail.code = NE_REAL_ARG_GT if X > 104.1
        fail.code = NE_REAL_ARG_LT if X < -1.8e+9
s17akc  fail.code = NE_REAL_ARG_GT if X > 104.1
        fail.code = NE_REAL_ARG_LT if X < -1.8e+9

s18adc  fail.code = NE_REAL_ARG_TOO_SMALL if 0.0 < X <= 2.23e-308
s18aec  fail.code = NE_REAL_ARG_GT if ABS(X) > 711.6
s18afc  fail.code = NE_REAL_ARG_GT if ABS(X) > 711.6
s18cdc  fail.code = NE_REAL_ARG_TOO_SMALL if 0.0 < X <= 2.23e-308

s19aac  fail.code = NE_REAL_ARG_GT if ABS(X) >= 49.5000
s19abc  fail.code = NE_REAL_ARG_GT if ABS(X) >= 49.5000
s19acc  fail.code = NE_REAL_ARG_GT if X > 997.26
s19adc  fail.code = NE_REAL_ARG_GT if X > 997.26

s21bcc  fail.code = NE_REAL_ARG_LT if an argument < 1.579e-205
        fail.code = NE_REAL_ARG_GE if an argument >= 3.774e+202
s21bdc  fail.code = NE_REAL_ARG_LT if an argument < 2.820e-103
        fail.code = NE_REAL_ARG_GT if an argument > 1.404e+102

(b) x01

The values of the mathematical constants are provided in the header file nagx01.h: 
X01AAC (pi)    = 3.1415926535897932
X01ABC (gamma) = 0.5772156649015329

(c) x02

The values of the machine constants are provided in the header file nagx02.h:

The basic parameters of the model 

X02BHC = 2
X02BJC = 53
X02BKC = -1021
X02BLC = 1024
X02DJC = TRUE
Derived parameters of the floating-point arithmetic 
X02AJC = 0x000000013ca00000 ( 1.11022302462516e-16 )
X02AKC = 0x0000000000100000 ( 2.22507385850721e-308 )
X02ALC = 0xffffffff7fefffff ( 1.79769313486231e+308 )
X02AMC = 0x0000000000100000 ( 2.22507385850721e-308 )
X02ANC = 0x0000000000100000 ( 2.22507385850721e-308 )
Parameters of other aspects of the computing environment 
X02AHC = 0x0000000046900000 ( 8.11296384146067e+31 )
X02BBC = 2147483647
X02BEC = 15
X02DAC = FALSE

5. Documentation

Each supported NAG C Library site is currently provided with a printed copy of the NAG C Library Manual (or Update). Additional copies are available for purchase; please refer to the NAG documentation order form (available on the NAG websites, see Section 6 (c)) for details of current prices.

6. Support from NAG

(a) Contact with NAG

Queries concerning this document or the implementation generally should be directed initially to your local Advisory Service. If you have difficulty in making contact locally, you can contact NAG directly at one of the addresses given in the Appendix. Users subscribing to the support service are encouraged to contact one of the NAG Response Centres (see below).

(b) NAG Response Centres

The NAG Response Centres are available for general enquiries from all users and also for technical queries from sites with an annually licensed product or support service.

The Response Centres are open during office hours, but contact is possible by fax, email and phone (answering machine) at all times.

When contacting a Response Centre please quote your NAG site reference and NAG product code (in this case CLIB606DA).

(c) NAG Websites

The NAG websites are an information service providing items of interest to users and prospective users of NAG products and services. The information is reviewed and updated regularly and includes implementation availability, descriptions of products, downloadable software, product documentation and technical reports. The NAG websites can be accessed at

http://www.nag.co.uk/

or

http://www.nag.com/ (in North America)

or

http://www.nag-j.co.jp/ (in Japan)

(d) NAG Electronic Newsletter

If you would like to be kept up to date with news from NAG you may want to register to receive our electronic newsletter, which will alert you to special offers, announcements about new products or product/service enhancements, case studies and NAG's event diary. To register visit one of our websites or contact us at nagnews@nag.co.uk.

7. User Feedback

Many factors influence the way NAG's products and services evolve and your ideas are invaluable in helping us to ensure that we meet your needs. If you would like to contribute to this process we would be pleased to receive your comments by email at feedback@nag.co.uk. Alternatively contact the appropriate NAG Response Centre who will be happy to record your comments.

Appendix - Contact Addresses

NAG Ltd
Wilkinson House
Jordan Hill Road
OXFORD  OX2 8DR                         NAG Ltd Response Centre
United Kingdom                          email: support@nag.co.uk
 
Tel: +44 (0)1865 511245                 Tel: +44 (0)1865 311744
Fax: +44 (0)1865 310139                 Fax: +44 (0)1865 310139
 
NAG Inc
1431 Opus Place, Suite 220
Downers Grove
IL 60515-1362                           NAG Inc Response Center
USA                                     email: infodesk@nag.com
 
Tel: +1 630 971 2337                    Tel: +1 630 971 2345
Fax: +1 630 971 2706                    Fax: +1 630 971 2706
 
Nihon NAG KK
Yaesu Nagaoka Building No. 6 
1-9-8 Minato
Chuo-ku
Tokyo
Japan
email: help@nag-j.co.jp

Tel: +81 (0)3 5542 6311
Fax: +81 (0)3 5542 6312

[NP3563/UN]