• 1. Introduction
  
  
• 2. Availability of Routines
  
  
• 3. General Information
  
  
  • 3.1. Accessing the Library
  • 3.2. Example Programs
  • 3.3. Interpretation of Bold Italicised Terms
  • 3.4. Explicit Output from NAG Routines
  • 3.5. Interface Blocks
    
    
• 4. Routine-specific Information
  
  
• 5. Documentation
  
  
• 6. Support from NAG
  
  
• 7. User Feedback
  
  
• Appendix - Contact Addresses

1. Introduction

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

The libraries supplied with this implementation have not been compiled in a manner that facilitates the use of multiple threads.

2. Availability of Routines

3. General Information

3.1. Accessing the Library

The shortcut

   Start | Programs | Numerical Algorithms Group | FL20 | Salford Fortran compiler with NAG static Lib. Command Prompt

may be used to start a command prompt window with the correct setting of the PATH environment variable for the compiler and Library.

Within this window you may compile your program in the following manner:

ftn77 /intl /logl /nolink driver.f

The program may be linked with the NAG library and MKL using the command

naglink driver

@echo off
echo load %1e.obj                           > slink.lst
echo load "%NAGLIBDIR%\lib\nag.lib"        >> slink.lst
echo load "%NAGLIBDIR%\mkl21\mkl_s.lib"    >> slink.lst
echo load "%NAGLIBDIR%\mkl21\kernel32.lib" >> slink.lst
echo load netapi32.dll                     >> slink.lst
echo file %1e.exe                          >> slink.lst
slink slink.lst

3.2. Example Programs

The example programs are most easily accessed by the script nagex.bat, 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, with results saved in a file.

If the first argument to the script is -mkl the example program is linked with the version of the NAG library that uses the MKL BLAS and LAPACK.

The example program concerned is specified by the argument to nagex.bat, e.g.

nagex c06eaf

In the NAG Fortran Library Manual, routine documents that have been typeset since Mark 12 present the example programs in a generalised form, using bold italicised terms as described in Section 3.3.

In other routine documents, the example programs are in single precision and require modification for use with double precision routines. This conversion can entail:

• Changing REAL or COMPLEX type specifications to REAL*8 or COMPLEX*16
• Changing certain intrinsic function references, e.g. REAL or FLOAT to DBLE, ALOG to DLOG, CMPLX to DCMPLX, and so on
• Changing real constants to double precision form, e.g. 0.1 or 0.1E0 to 0.1D0

The example programs supplied to a site in machine-readable form have been modified as necessary so that they are suitable for immediate execution. 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 static library, using the NAG BLAS and LAPACK routines. Running the examples with non-NAG BLAS or LAPACK may give slightly different results.

3.3. Interpretation of Bold Italicised Terms

real                 - DOUBLE PRECISION (REAL*8)
basic precision      - double precision
complex              - COMPLEX*16
additional precision - quadruple precision (REAL*16,COMPLEX*32)
machine precision    - the machine precision, see the value
                       returned by X02AJF in Section 4

Thus a parameter described as real should be declared as DOUBLE PRECISION in your program. If a routine accumulates an inner product in additional precision, it is using software to simulate quadruple precision.

In routine documents that have been typeset since Mark 12 additional bold italicised terms are used in the published example programs and they must be interpreted as follows:

real as an intrinsic function name - DBLE
imag                               - DIMAG
cmplx                              - DCMPLX
conjg                              - DCONJG
e in constants, e.g. 1.0e-4        - D, e.g. 1.0D-4
e in formats, e.g. e12.4           - D, e.g. D12.4

All references to routines in Chapter F07 - Linear Equations (LAPACK) and Chapter F08 - Least-squares and Eigenvalue Problems (LAPACK) use the LAPACK name, not the NAG F07/F08 name. The LAPACK name is precision dependent, and hence the name appears in a bold italicised typeface.

The typeset examples use the single precision form of the LAPACK name. To convert this name to its double precision form, change the first character either from S to D or C to Z as appropriate.
For example:

sgetrf refers to the LAPACK routine name - DGETRF
cpotrs                                   - ZPOTRS

3.4. Explicit Output from NAG Routines

Certain routines produce explicit error messages and advisory messages via output units which either have default values or can be reset by using X04AAF for error messages and X04ABF for advisory messages. (The default values are given in Section 4.) The maximum record lengths of error messages and advisory messages (including carriage control characters) are 80 characters, except where otherwise specified.

3.5. Interface Blocks

The NAG Fortran Library Interface Blocks define the type and arguments of each user callable NAG Fortran Library routine. These are not essential to calling the NAG Fortran Library from Fortran 90/95 programs. Their purpose is to allow the Fortran 90/95 compiler to check that NAG Fortran Library routines are called correctly. The interface blocks enable the compiler to check that:

(a) Subroutines are called as such
(b) Functions are declared with the right type
(c) The correct number of arguments are passed
(d) All arguments match in type and structure

These interface blocks have been generated automatically by analysing the source code for the NAG Fortran Library. As a consequence, and because these files have been thoroughly tested, their use is recommended in preference to writing your own declarations.

The NAG Fortran Library Interface Block files are organised by Library chapter. The module names are:

nag_f77_a_chapter
nag_f77_c_chapter
nag_f77_d_chapter
nag_f77_e_chapter
nag_f77_f_chapter
nag_f77_g_chapter
nag_f77_h_chapter
nag_f77_m_chapter
nag_f77_p_chapter
nag_f77_s_chapter
nag_f77_x_chapter

In order to make use of these modules from existing Fortran 77 code the following changes need to be made:

• Add a USE statement for each of the module files for the chapters of the NAG Fortran Library that your program calls directly. Often only one USE statement will be required.
• Delete all EXTERNAL statements for NAG Fortran Library routines. These are now declared in the module(s).
• Delete the type declarations for any NAG Fortran Library functions. These are now declared in the module(s).

These changes are illustrated by showing the conversion of the Fortran 77 version of the example program for NAG Fortran Library routine S18DEF. Please note that this is not exactly the same as the example program that is distributed with this implementation. Each change is surrounded by comments boxed with asterisks.

*     S18DEF Example Program Text
*     Mark 14 Revised.  NAG Copyright 1989.
*******************************************************************
* Add USE statement for relevant chapters                         *
      USE NAG_F77_S_CHAPTER
*                                                                 *
*******************************************************************
*     .. Parameters ..
      INTEGER          NIN, NOUT
      PARAMETER        (NIN=5,NOUT=6)
      INTEGER          N
      PARAMETER        (N=2)
*     .. Local Scalars ..
      COMPLEX*16       Z
      DOUBLE PRECISION FNU
      INTEGER          IFAIL, NZ
      CHARACTER*1      SCALE
*     .. Local Arrays ..
      COMPLEX*16       CY(N)
*     .. External Subroutines ..
*******************************************************************
* EXTERNAL declarations need to be removed (and type declarations *
*  for functions).                                                *
C      EXTERNAL         S18DEF
*                                                                 *
*******************************************************************
*     .. Executable Statements ..
      WRITE (NOUT,*) 'S18DEF Example Program Results'
*     Skip heading in data file
      READ (NIN,*)
      WRITE (NOUT,*)
      WRITE (NOUT,99999) 'Calling with N =', N
      WRITE (NOUT,*)
      WRITE (NOUT,*)
     +'   FNU            Z        SCALE       CY(1)              CY(2)
     +   NZ IFAIL'
      WRITE (NOUT,*)
   20 READ (NIN,*,END=40) FNU, Z, SCALE
      IFAIL = 0
*
      CALL S18DEF(FNU,Z,N,SCALE,CY,NZ,IFAIL)
*
      WRITE (NOUT,99998) FNU, Z, SCALE, CY(1), CY(2), NZ, IFAIL
      GO TO 20
   40 STOP
*
99999 FORMAT (1X,A,I2)
99998 FORMAT (1X,F7.4,'  (',F7.3,',',F7.3,')   ',A,
     +       2('  (',F7.3,',',F7.3,')'),I4,I4)
      END

4. Routine-specific Information

(a) D03

(b) F06, F07 and F08

(c) G02

(d) P01

(e) S07 - S21

S07AAF  F(1)   = 1.0D+13
        F(2)   = 1.0D-14
 
S10AAF  E(1)   = 18.50
S10ABF  E(1)   = 708.0
S10ACF  E(1)   = 708.0
 
S13AAF  x(hi)  = 708.2
S13ACF  x(hi)  = 1.0D+16
S13ADF  x(hi)  = 1.0D+17
 
S14AAF  IFAIL  = 1 if X > 170.0
        IFAIL  = 2 if X < -170.0
        IFAIL  = 3 if abs(X) < 2.58D-308
S14ABF  IFAIL  = 2 if X > 2.55D+305
 
S15ADF  x(hi)  = 26.6
        x(low) = -6.25
S15AEF  x(hi)  = 6.25
 
S17ACF  IFAIL  = 1 if X > 1.0D+16
S17ADF  IFAIL  = 1 if X > 1.0D+16
        IFAIL  = 3 if 0.0 < X <= 2.58D-308
S17AEF  IFAIL  = 1 if abs(X) > 1.0D+16
S17AFF  IFAIL  = 1 if abs(X) > 1.0D+16
S17AGF  IFAIL  = 1 if X > 103.8
        IFAIL  = 2 if X < -5.6D+10
S17AHF  IFAIL  = 1 if X > 104.1
        IFAIL  = 2 if X < -5.6D+10
S17AJF  IFAIL  = 1 if X > 104.1
        IFAIL  = 2 if X < -1.8D+9
S17AKF  IFAIL  = 1 if X > 104.1
        IFAIL  = 2 if X < -1.8D+9
S17DCF  IFAIL  = 2 if abs (Z) < 3.93D-305
        IFAIL  = 4 if abs (Z) or FNU+N-1 > 3.27D+4
        IFAIL  = 5 if abs (Z) or FNU+N-1 > 1.07D+9
S17DEF  IFAIL  = 2 if imag (Z) > 700.0
        IFAIL  = 3 if abs (Z) or FNU+N-1 > 3.27D+4
        IFAIL  = 4 if abs (Z) or FNU+N-1 > 1.07D+9
S17DGF  IFAIL  = 3 if abs (Z) > 1.02D+3
        IFAIL  = 4 if abs (Z) > 1.04D+6
S17DHF  IFAIL  = 3 if abs (Z) > 1.02D+3
        IFAIL  = 4 if abs (Z) > 1.04D+6
S17DLF  IFAIL  = 2 if abs (Z) < 3.93D-305
        IFAIL  = 4 if abs (Z) or FNU+N-1 > 3.27D+4
        IFAIL  = 5 if abs (Z) or FNU+N-1 > 1.07D+9
 
S18ADF  IFAIL  = 2 if 0.0 < X <= 2.58D-308
S18AEF  IFAIL  = 1 if abs(X) > 711.5
S18AFF  IFAIL  = 1 if abs(X) > 711.5
S18CDF  IFAIL  = 2 if 0.0 < X <= 2.58D-308
S18DCF  IFAIL  = 2 if abs (Z) < 3.93D-305
        IFAIL  = 4 if abs (Z) or FNU+N-1 > 3.27D+4
        IFAIL  = 5 if abs (Z) or FNU+N-1 > 1.07D+9
S18DEF  IFAIL  = 2 if real (Z) > 700.0
        IFAIL  = 3 if abs (Z) or FNU+N-1 > 3.27D+4
        IFAIL  = 4 if abs (Z) or FNU+N-1 > 1.07D+9
 
S19AAF  IFAIL  = 1 if abs(x) >= 49.50
S19ABF  IFAIL  = 1 if abs(x) >= 49.50
S19ACF  IFAIL  = 1 if X > 997.06
S19ADF  IFAIL  = 1 if X > 997.06
 
S21BCF  IFAIL  = 3 if an argument < 1.740D-205
        IFAIL  = 4 if an argument >= 3.424D+202
S21BDF  IFAIL  = 3 if an argument < 2.960D-103
        IFAIL  = 4 if an argument >= 1.337D+102

(f) X01

X01AAF (PI)    = 3.1415926535897932
X01ABF (GAMMA) = 0.5772156649015329

(g) X02

The basic parameters of the model

X02BHF =      2
X02BJF =     53
X02BKF =  -1021
X02BLF =   1024
X02DJF =  .TRUE.

X02AJF = 1.11130722679765D-16
X02AKF = 2.22507385850721D-308
X02ALF = 1.79769313486231D+308
X02AMF = 2.57466740049304D-308
X02ANF = 4.45014771701453D-308

X02AHF = 4.61168601842738D+18
X02BBF = 2147483647
X02BEF = 15
X02DAF = .FALSE.

(h) X04

5. Documentation

A full online version of the NAG Fortran Library Manual is supplied in the form of Portable Document Format (PDF) files, with an HTML index. The introductory material is also provided as HTML files. The main index is a fully linked contents document pointing to all the available PDF (and where available HTML) files.

The manual can be viewed directly from the distribution CD, and may have also been installed on local hard disk. If it has been installed on your PC, there will be a shortcut

   Start | Programs | Numerical Algorithms Group | FL20 | Manual

which will start your HTML browser at the contents page. This page may be found on the distribution CD as \Manual\html\mark20.html.

In addition the following are provided in the doc folder:

• un.html - Users' Note (this document)
• blas_lapack_to_nag - BLAS/F06, LAPACK/F07 and LAPACK/F08 listing
• nag_to_blas_lapack - F06/BLAS, F07/LAPACK and F08/LAPACK listing

   Start | Programs | Numerical Algorithms Group | FL20 | Salford Fortran compiler NAG static Lib. User Note

6. Support from NAG

(a) Contact with NAG

(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 (in this case FLW3220DSL).

(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

http://www.nag.co.uk/, http://www.nag.com/ (in North America) or http://www.nag-j.co.jp/ (in Japan)

(d) NAG Electronic Newsletter

7. User Feedback

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
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