NAG C Library, Mark 8

CLAI308DAL - License Managed

IBM RISC, 32-bit, AIX, xlc

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 refers to the "Users' Note for your implementation", you should consult this note.

In addition, NAG recommends that before calling any library routine you should read the following reference material (see Section 5):

(a) Essential Introduction
(b) Chapter Introduction
(c) Routine Document

2. Availability of Routines

All routines listed in the chapter contents documents of the NAG C Library Manual, Mark 8 are available in this implementation. Please consult Mark 8 News (see Section 5) for a list of new routines and for a list of routines 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

This section shows two ways of accessing the library depending on the location of the compiled libraries.

3.1.1. Libraries NOT in the linker search path

In this section we assume that the library and the NAG include files have been installed in the directory [INSTALL_DIR].

By default [INSTALL_DIR] (see Installer's Note (in.html)) is /opt/NAG/clai308dal or /usr/local/NAG/clai308dal depending on your system; however it could have been changed by the installer. To identify [INSTALL_DIR] for this installation:

To use the NAG C Library and the IBM ESSL library, you may link in the following manner: 
xlc driver.c -I[INSTALL_DIR]/include \
[INSTALL_DIR]/lib/libnagc_essl.a -lessl -lpthread -lm
where driver.c is your application program;

or 


xlc driver.c -I[INSTALL_DIR]/include \
[INSTALL_DIR]/lib/libnagc_essl.so -lessl -lpthread -lm
if the shareable library is required.

However, if you prefer to link to a version of the NAG library which does not require the use of the IBM ESSL Library, you may wish to use the self-contained libraries as follows: 


xlc driver.c -I[INSTALL_DIR]/include \
[INSTALL_DIR]/lib/libnagc_nag.a -lpthread -lm
or 

xlc driver.c -I[INSTALL_DIR]/include \
[INSTALL_DIR]/lib/libnagc_nag.so -lpthread -lm
if the shareable library is required. Note the use of xlc_r is recommended in all cases where a multi-threaded application is being developed.

Please note that using a self-contained library may result in some degradation in the performance of your application.

If your application has been linked with the shareable NAG Library then the environment variable LD_LIBRARY_PATH must be set (or extended) to allow run time linkage.

In the C shell type: 

      setenv LD_LIBRARY_PATH [INSTALL_DIR]/lib
to set LD_LIBRARY_PATH, or 
   setenv LD_LIBRARY_PATH [INSTALL_DIR]/lib:${LD_LIBRARY_PATH}
to extend LD_LIBRARY_PATH if you already have it set.

In the Bourne shell, type: 

   LD_LIBRARY_PATH=[INSTALL_DIR]/lib
   export LD_LIBRARY_PATH
to set LD_LIBRARY_PATH, or 

   LD_LIBRARY_PATH=[INSTALL_DIR]/lib:${LD_LIBRARY_PATH}
   export LD_LIBRARY_PATH
to extend LD_LIBRARY_PATH if you already have it set.

3.1.2. Libraries in the linker search path

In this section we assume that the compiled libraries and the include files are pointed at by symbolic links from a directory in the search path of the linker, such as /usr/lib.

To use the NAG C Library and the IBM ESSL library, you may link in the following manner: 


xlc driver.c -lnagc_essl -lessl -lpthread -lm
To use the dynamic library libnagc_essl.so you need the -brtl loader flag to switch dynamic binding on: 

xlc -brtl driver.c -lnagc_essl -lessl -lpthread -lm
Note the use of xlc_r is recommended in all cases where a multi-threaded application is being developed.

However, if you prefer to link to a version of the NAG C library which does not require the use of the IBM ESSL library, you may wish to use the self-contained libraries as follows: 


xlc driver.c -lnagc_nag -lpthread -lm
This will usually link to the static library in preference to the shareable library if both the libraries are at the same location.

To use the dynamic library libnagc_nag.so you need the -brtl loader flag: 

xlc -brtl driver.c -lnagc_nag -lpthread -lm
Please note that using a self-contained library may result in some degradation in the performance of your application.

If your application has been linked with the shareable NAG then the environment variable LD_LIBRARY_PATH must be set (or extended) to allow run time linkage.

In the C shell type: 

   setenv LD_LIBRARY_PATH [INSTALL_DIR]/lib
to set LD_LIBRARY_PATH, or 
   setenv LD_LIBRARY_PATH [INSTALL_DIR]/lib:${LD_LIBRARY_PATH}
to extend LD_LIBRARY_PATH if you already have it set.

In the Bourne shell, type: 

   LD_LIBRARY_PATH=[INSTALL_DIR]/lib
   export LD_LIBRARY_PATH
to set LD_LIBRARY_PATH, or 

   LD_LIBRARY_PATH=[INSTALL_DIR]/lib:${LD_LIBRARY_PATH}
   export LD_LIBRARY_PATH
to extend LD_LIBRARY_PATH if you already have it set.

3.2. Example Programs

The directory [INSTALL_DIR]/scripts contains four scripts nagc_example_essl, nagc_example_shar_essl, nagc_example and nagc_example_shar.

The example programs are most easily accessed by one of the commands

Each command will provide you with a copy of an example program (and its data, if any), compile the program and link it with the appropriate libraries (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 the command, e.g. 

nagc_example d01ajc
will copy the example program into the file d01ajce.c in the current directory and process it to produce the example program results.

The example programs are supplied in machine-readable form. They are suitable for immediate usage. Note that the distributed example programs are those used in this implementation and may not correspond exactly with the programs published in the manual. The distributed example programs should be used in preference wherever possible.

The distributed example results are those obtained with the NAG self-contained static library libnagc_nag.a, (using the NAG BLAS and LAPACK routines). Running the examples with vendor BLAS or LAPACK may give slightly different results.

4. Routine-specific Information

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

  1. F06, F07 and F08

    In this implementation calls to the NAG version of the following Basic Linear Algebra Subprograms (BLAS) and linear algebra routines (LAPACK) are included in the libraries libnagc_essl.a and libnagc_essl.so to avoid problems with the vendor version: 

      
dgeqrf dgetrf dgetri dgetrs dpotrf dpotri dpotrs dpptrf dpptri dpptrs dtrtri
dspsv
zgeqrf zgetrf zgetri zgetrs zpotrf zpotri zpotrs zpptrf zpptri zpptrs ztrtri
zspsv zhpsv

  2. 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)      = 1.8500e+1
s10abc  fail.code = NE_REAL_ARG_GT if X > 7.080e+2
s10acc  fail.code = NE_REAL_ARG_GT if X > 7.080e+2

s13aac  X(hi)     = 7.083e+2
s13acc  X(hi)     = 1.0e+16
s13adc  X(hi)     = 1.0e+17

s14aac  fail.code = NE_REAL_ARG_GT if X > 1.70e+2
        fail.code = NE_REAL_ARG_LT if X < -1.70e+2
        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 > 1.038e+2
        fail.code = NE_REAL_ARG_LT if X < -5.6e+10
s17ahc  fail.code = NE_REAL_ARG_GT if X > 1.041e+2
        fail.code = NE_REAL_ARG_LT if X < -5.6e+10
s17ajc  fail.code = NE_REAL_ARG_GT if X > 1.041e+2
        fail.code = NE_REAL_ARG_LT if X < -1.8e+9
s17akc  fail.code = NE_REAL_ARG_GT if X > 1.041e+2
        fail.code = NE_REAL_ARG_LT if X < -1.8e+9

s18adc  fail.code = NE_REAL_ARG_TOO_SMALL if 0.0D+00 < X <= 2.23e-308
s18aec  fail.code = NE_REAL_ARG_GT if ABS(X) > 7.116e+2
s18afc  fail.code = NE_REAL_ARG_GT if ABS(X) > 7.116e+2
s18cdc  fail.code = NE_REAL_ARG_TOO_SMALL if 0.0D+00 < X <= 2.23e-308

s19aac  fail.code = NE_REAL_ARG_GT if ABS(X) >= 4.95000e+1
s19abc  fail.code = NE_REAL_ARG_GT if ABS(X) >= 4.95000e+1
s19acc  fail.code = NE_REAL_ARG_GT if X > 9.9726e+2
s19adc  fail.code = NE_REAL_ARG_GT if X > 9.9726e+2

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

  3. x01

    The values of the mathematical constants are provided in the header file nagx01.h 
    X01AAC (pi)    = 3.14159265358979323846e+00
X01ABC (gamma) = 0.5772156649015328606e+00

  4. x02

    The values of the machine constants are provided in 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 = 1.11022302462516e-16
X02AKC = 2.22507385850721e-308
X02ALC = 1.79769313486231e+308
X02AMC = 2.22507385850721e-308
X02ANC = 2.22507385850721e-308

    Parameters of other aspects of the computing environment 

    X02AHC = 8.11296384146067e+31
X02BBC = 2147483647
X02BEC = 15
X02DAC = FALSE

5. Documentation

A full online version of the NAG C Library Manual is supplied in the form of Portable Document Format (PDF) files, with an HTML index, in the nagdoc_cl08 directory. The introductory material is also provided as HTML files in the nagdoc_cl08 directory.

A main index file has been provided (nagdoc_cl08/html/mark8.html) which contains a fully linked contents document pointing to all the available PDF (and where available HTML) files. Use your HTML browser to navigate from here.

In addition the following are provided:

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 it helps us deal with your enquiry quickly if you can quote your NAG site reference and NAG product code (CLAI308DAL).

(c) NAG Websites

The NAG websites provide information about implementation availability, descriptions of products, downloadable software, product documentation and technical reports. The NAG websites can be accessed at the following URLs:

http://www.nag.co.uk/, http://www.nag.com/ or http://www.nag-j.co.jp/

(d) NAG Electronic Newsletter

If you would like to be kept up to date with news from NAG then please register to receive our free electronic newsletter, which will alert you to special offers, announcements about new products or product/service enhancements, customer stories and NAG's event diary. You can register via one of our websites, or by contacting us at nagnews@nag.co.uk.

(e) Product Registration

To ensure that you receive information on updates and other relevant announcements, please register this product with us. For NAG Library products this may be accomplished by filling in the online registration form at http://www.nag.co.uk/numeric/Library_Registration.asp.

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. Please contact your local NAG Response Centre (shown below).

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: support@nag.com

Tel: +1 630 971 2337                    Tel: +1 630 971 2337
Fax: +1 630 971 2706                    Fax: +1 630 971 2706

Nihon NAG KK
Hatchobori Frontier Building 2F
4-9-9
Hatchobori
Chuo-ku
Tokyo
104-0032
Japan
email: help@nag-j.co.jp

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