CLSG606DA Users' Note

NAG C Library, Mark 6

CLSG606DA

Silicon Graphics (IRIX 6)

Users' Note

1. Introduction
2. Availability of Functions
3. General Information
4. Function-specific Information
5. Documentation
6. Support from NAG
7. User Feedback
Appendix - Contact Addresses

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

This implementation includes libraries in both archive and dynamic share object (DSO) forms for the following combinations of Application Binary Interfaces (ABI) and Instruction Set Architectures (ISA):

high performance 32-bit (-n32) mode using -mips3
high performance 32-bit (-n32) mode using -mips4
64-bit mode using -mips3
64-bit mode using -mips4

3.1. Accessing the Library

Assuming that the symbolic links for libnagc.a and libnagc.so have been created in the appropriate system library directories which appear in the search path of the linker and that the NAG include files have been moved to /usr/include, then you may link to the NAG C Library in the following manner:

cc driver.c -lnagc -lm -lpthread

where driver.c is your application program.

The specific library used by the linker depends on the compilation options, if any, specified by the user and on the system processor. On systems such as the Silicon Graphics Power Indigo2, based on a R8000 processor, the default, if the SGI_ABI environment variable has not been set, is 64-bit and MIPS IV.

On systems such as the Silicon Graphics Origin 2000, based on a R10000 processor, the default, if the SGI_ABI environment variable has not been set, is high performance 32-bit (-n32) and MIPS IV.

Note that the choice of the library linked to can be overridden by specifying the application binary interface (ABI), that is -n32 or -64, and the instruction set architecture (ISA), that is -mips3 or -mips4.

It may be necessary to append to the high performance 32-bit (-n32) and 64-bit default library search paths the location of the NAG libraries.

In the C shell use the command:

setenv LD_LIBRARYN32_PATH '/usr/lib32/mips3:/usr/lib32/mips4'

for high performance 32-bit (-n32) programs and

setenv LD_LIBRARY64_PATH '/usr/lib64/mips3:/usr/lib64/mips4'

for 64-bit programs.

In the Bourne shell the equivalent commands would be:

LD_LIBRARYN32_PATH='/usr/lib32/mips3:/usr/lib32/mips4'
export LD_LIBRARYN32_PATH

and

LD_LIBRARY64_PATH='/usr/lib64/mips3:/usr/lib64/mips4'
export LD_LIBRARY64_PATH

If these environment variables are not set, the program may exhibit a fatal error indicating that it is not able to map successfully soname 'libnag.so'. For more information concerning runtime linker options, please refer to the 'rld' man page.

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:

un.html - Users' Note (this document)
calls - a list of functions called directly or indirectly by each function in the library, and by each example program

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 f_i(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)     = 5.6e+14
s13adc  X(hi)     = 5.6e+14

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 > 5.6e+14
s17adc  fail.code = NE_REAL_ARG_GT if X > 5.6e+14
        fail.code = NE_REAL_ARG_TOO_SMALL if X <= 2.23e-308
s17aec  fail.code = NE_REAL_ARG_GT if ABS(X) > 5.6e+14
s17afc  fail.code = NE_REAL_ARG_GT if ABS(X) > 5.6e+14
s17agc  fail.code = NE_REAL_ARG_GT if X > 103.8
        fail.code = NE_REAL_ARG_LT if X < -8.9e+9
s17ahc  fail.code = NE_REAL_ARG_GT if X > 104.1
        fail.code = NE_REAL_ARG_LT if X < -8.9e+9
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 = 1.1102230246251e-16 
X02AKC = 2.2250738585072e-308 
X02ALC = 1.7976931348623e+308 
X02AMC = 2.2250738585072e-308 
X02ANC = 2.2250738585072e-308

Parameters of other aspects of the computing environment

X02AHC = 5.62949953421312e+14 
X02BBC = 2147483647           (for 32-bit libraries)
X02BBC = 9223372036854775807  (for 64-bit libraries)
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 CLSG606DA).

(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/

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

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 delighted to receive your comments. We have provided a short survey on our website at www.nag.co.uk/local/feedback to enable you to provide this feedback. Alternatively feel free to contact the appropriate NAG Response Centre who will be happy either to record your comments or to send you a printed copy of the survey.

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

[NP3562/UN]