NAG Fortran Library, Mark 21

FLW6I21DCL - License Managed

Windows x64 XP/Vista, Intel Visual Fortran

Users' Note



Contents


1. Introduction

This document is essential reading for every user of the NAG Fortran Library implementation specified in the title. It provides implementation-specific detail that augments the information provided in the NAG Mark 21 Library Manual (which we will refer to as the 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

The libraries supplied with this implementation have been compiled in a manner that facilitates the use of multiple threads.

If you intend to use the NAG library within a multithreaded application please refer to the document on Thread Safety in the Library Manual (see Section 5).

2. Availability of Routines

All routines listed in the chapter contents documents of the Library Manual are available in this implementation. Please consult Mark 21 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

In this section we assume that the Library subfolder flw6i21dcl has been installed beneath the default folder:
  c:\Program Files\NAG\FL21
If this folder does not exist, please consult the system manager (or the person who did the installation).

We also assume that the default shortcut for the Library command prompt is placed in the Start Menu under:

  Start|All Programs|NAG|FL21|

If this shortcut does not exist, please consult the system manager (or the person who did the installation).

3.1.1. From a command window

To access this implementation from a command window some environment variables need to be set.

The shortcut:

  Start|All Programs|NAG|FL21|NAG Fortran Library -
      Intel Visual Fortran compiler (FLW6I21DCL). Command Prompt

may be used to start a command prompt window with the correct settings for the INCLUDE, LIB and PATH environment variables for the Library and the supplied MKL.

If the shortcut is not used, you can set the environment variables by running the batch file envvars.bat for this implementation. The default location of this file is:

  c:\Program Files\NAG\FL21\flw6i21dcl\batch\envvars.bat
If the file is not in the default location, you can locate it by searching for the file envvars.bat containing flw6i21dcl.

You may then compile and link to the NAG Fortran Library on the command line using one of the following commands:

  ifort /MT driver.f nag_mkl.lib mkl_em64t.lib libguide.lib mkl_lapack.lib
  ifort /MT driver.f nag_nag.lib
  ifort /MD driver.f nag_mkl_md.lib mkl_dll.lib libguide.lib
  ifort /MD driver.f nag_nag_md.lib
  ifort /MD driver.f FLW6I21DC_mkl.lib mkl_dll.lib libguide.lib
  ifort /MD driver.f FLW6I21DC_nag.lib
where driver.f is your application program. The order of the libraries is important because certain parts of the MKL should not be used (see Section 4).

The first two commands use libraries compiled with the /MT option. The first command will use the static library without the NAG version of the BLAS/LAPACK procedures nag_mkl.lib and the MKL static libraries. The second command will use the library with the NAG version of the BLAS/LAPACK procedures nag_nag.lib. The option /MT must be used to ensure linking with the correct run-time libraries (multithreaded static run-time libraries in this case).

The third and fourth commands use static libraries compiled with the /MD option. The third command will use the static library without the NAG version of the BLAS/LAPACK procedures nag_mkl_md.lib and the MKL DLL. The fourth command will use the library with the NAG version of the BLAS/LAPACK procedures nag_nag_md.lib. The option /MD must be used to ensure linking with the correct run-time libraries (multithreaded dynamic-link run-time libraries in this case).

The last two commands use the DLL. The fifth command will use the DLL without the NAG version of the BLAS/LAPACK procedures FLW6I21DC_mkl.lib and the MKL DLL. The last command will use the DLL with the NAG version of the BLAS/LAPACK procedures FLW6I21DC_nag.lib. The option /MD must be used to ensure linking with the correct run-time libraries.

In the case where more than one library is used, you could simplify the command line by using the librarian to combine the libraries into a single library. For example you could use:

  lib /out:my_lib.lib nag_mkl.lib mkl_em64t.lib libguide.lib mkl_lapack.lib
As mentioned before the order of the libraries is important because certain parts of the MKL should not be used (see Section 4), you can then replace the first command with:
  ifort /MT driver.f my_lib.lib
Please note that the Intel Visual Fortran compiler environment variables must be set in the command window. For more details refer to the User's Guide of the compiler.

3.1.2. From MS Visual Studio 2005

The instructions given here are for Visual Studio 2005. Other versions may vary.

Once Visual Studio has been opened, it is possible to set up the directories for use with Intel Fortran in this and all subsequent projects which use this compiler. One way to do so is:

  1. Select the Tools pull down menu, move the mouse over Options and left-click on it.
  2. In the Options window, move the mouse over the left window pane to Intel(R) Fortran and left-click on it.
  3. Move the mouse to the right window pane and left-click on the '...' to the right of the Libraries panel.
  4. Add the path to the NAG Library to the Set Directory List window. The default location is:
    "c:\Program Files\NAG\FL21\flw6i21dcl\lib"
  5. If you intend to use the MKL libraries then you need to add the path to the MKL libraries after the path to the NAG Library. The default location is:
    "c:\Program Files\NAG\FL21\flw6i21dcl\MKL_em64t_9.1\lib"
  6. Left-click on the OK button in the Set Directory List window.
  7. Move the mouse to the right window pane and left-click on the '...' to the right of the Includes panel.
  8. Add the path to the NAG interface blocks to the Set Directory List window. The default location is:
    "c:\Program Files\NAG\FL21\flw6i21dcl\nag_interface_blocks"
  9. Left-click on the OK button in the Set Directory List window.
  10. Left-click on the OK button in the Options window.
From now, if an Intel Fortran project requires a library or NAG interface block then the library and interface block do not need the full path to be specified.

The interface block is simply accessed by inserting a USE statement as described in greater detail in Section 3.5.

Whilst the above changes will apply to every Intel Fortran project, the following tasks need to be performed for each individual Intel Fortran project.

You need first to ensure that you are using the 64-bit compiler. This can be done by selecting x64 in the Target Platform. You can do this from the Toolbar via Options|Intel(R)Fortran. You also need to set the Active Solution Platform to x64. You can do this from the Toolbar or alternatively via the Build|Configuration Manager menus.

The Library is designed to be run in fully optimised mode, so to avoid any warning messages, you might decide to set the active configuration to Release. You can do this from the Toolbar or alternatively via the Build|Configuration Manager menus. If you work in Debug mode, you may receive a warning message about conflicting C runtime libraries. This is usually harmless.

There are a number of ways to add the NAG Library to the project. We describe just two; choose the one that most suits you.

If the Solution Explorer window is open then make sure that group project (the first line) is NOT selected. From the Project menu, choose the project Properties item. (Alternatively right click on a specific single project in the Solution Explorer and choose Properties.)

From the form, click Linker in the leftmost panel and then choose Input. The right hand panel will now have an Additional Dependencies entry, and you need to type nag_mkl.lib libguide.lib mkl_c.lib in this location to use the nag_mkl.lib library and MKL. Please note that the three libraries are separated by a space only and that nag_mkl.lib must be the first one. Press the OK button. If you wish to use the self-contained NAG Library then you need to add nag_nag.lib instead.

The Properties information may also be accessed via the Toolbar. With the project selected in Solution Explorer, choose the Properties Window button on the Toolbar. In the ensuing window choose then the rightmost Property Pages icon. As in the paragraph above, from the form click Linker in the leftmost panel and then choose Input. The right hand panel will now have an Additional Dependencies entry, and you need to type the names of the relevant libraries in this location. Press the OK button.

Before you can compile the project you need to specify the correct runtime library needed. From the Properties Window, click Fortran in the leftmost panel and then choose Libraries. The right hand panel will now have a Runtime Library entry, and you need to select Multithreaded if your project uses one of the two libraries nag_nag.lib or nag_mkl.lib. If your projects uses any of the other NAG libraries you need to select Multithreaded DLL. After you select the correct runtime library press the OK button.

Please note that if you select Multithreaded DLL you need to ensure that the required DLLs are accessible at runtime. The PATH environment variable must be set such that the location of the NAG Fortran DLLs, specifically the folder install dir\bin, is on the path. If the MKL version of the DLL is required, the location of the MKL DLLs, install dir\mkl_em64t_9.1\bin must also be on the path, but should appear after the install dir\bin folder.

In summary the setting of the project Additional Dependencies, the project Runtime Library and the PATH environment variable must be consistent as follows:

The project should now compile and link using the appropriate choice from the Build menu.

To run a program that does not require input or output redirected from standard input or standard output, from within the Microsoft Development Environment, the program may be executed via the Debug menu (by selecting Start Without Debugging, for example).

If a data file needs to be attached to the standard input or the output of a program needs to be redirected to the standard output, we recommend that you run the executable from a command prompt window to avoid the limitations of the current version of Visual Studio 2005.

3.2. Example Programs

The example programs are most easily accessed by the batch files nag_example.bat, nag_example_mkl.bat, nag_example_md.bat, nag_example_mkl_md.bat, nag_example_dll.bat or nag_example_mkl_dll.bat.

The batch files need the environment variable NAG_FLW6I21DCL.

As mentioned in Section 3.1.1, the installation procedure provides a shortcut which starts a Command Prompt with local environment variables. The environment variables include NAG_FLW6I21DCL. This shortcut is placed in the Start Menu under

  Start|All Programs|NAG|FL21|NAG Fortran Library -
      Intel Visual Fortran compiler (FLW6I21DCL). Command Prompt
If the shortcut is not used, you need to set this environment variable. You can set this environment variable by running the batch file envvars.bat for this implementation. The default location of this file is:
  c:\Program Files\NAG\FL21\flw6i21dcl\batch\envvars.bat
If the file is not in the default location, you can locate it by searching for the file envvars.bat containing flw6i21dcl.

nag_example_mkl.bat will provide you with a copy of an example program (and its data, if any), compile the program and link it with the library nag_mkl.lib and the MKL. Finally, the executable program will be run. The example program concerned is specified by the argument to nag_example_mkl.bat, e.g.

  nag_example_mkl  e04ucf
will copy the example program and its data into the files e04ucfe.f and e04ucfe.d in the current folder, compile and link e04ucfe.f to create the executable (this is same as using ifort /MT e04ucfe.f nag_mkl.lib mkl_em64t.lib libguide.lib mkl_lapack.lib in Section 3.1.1) and run the executable to produce the example program results in the file e04ucfe.r.

Alternatively you could use:

  nag_example          e04ucf   (links with nag_nag.lib)
  nag_example_mkl_md   e04ucf   (links with nag_mkl_md.lib and MKL)
  nag_example_md       e04ucf   (links with nag_nag_md.lib)
  nag_example_mkl_dll  e04ucf   (links with FLW6I21DC_mkl.lib and MKL)
  nag_example_dll      e04ucf   (links with FLW6I21DC_nag.lib)

The main difference between nag_example_mkl.bat and the other batch files is in the way the executable is created. While nag_example_mkl.bat uses the static library nag_mkl.lib and the MKL libraries to create the executable:

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 Library Manual. The distributed example programs should be used in preference wherever possible.

The distributed example results are those obtained with the library nag_nag.lib, (using the NAG BLAS and LAPACK routines). Running the examples with MKL BLAS or LAPACK may give slightly different results.

3.3. Interpretation of Bold Italicised Terms

For this double precision implementation, the bold italicised terms used in the Library Manual should be interpreted as follows:
real or double precision  - DOUBLE PRECISION (REAL*8)
basic precision           - double precision
complex or complex*16     - 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 or double precision 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.

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.

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
These are supplied in pre-compiled form (.mod files).

If you use the Library command prompt shortcut or set the environment variables by running the batch file envvars.bat for this implementation (see Section 3.1.1), you can use any of the commands described in Section 3.1.1 to access these modules since the environment variable INCLUDE will be set.

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

The above steps need to be done for each unit (main program, function or subroutine) in your code.

These changes are illustrated by showing the conversion of the Fortran 77 version of the example program for NAG Fortran Library routine D01DAF. 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.

*     D01DAF Example Program Text
*****************************************************
* Add USE statements for relevant chapters          *
      USE NAG_F77_D_CHAPTER
*                                                   *
*****************************************************
*     .. Parameters ..
      INTEGER          NOUT
      PARAMETER        (NOUT=6)
*     .. Local Scalars ..
      DOUBLE PRECISION ABSACC, ANS, YA, YB
      INTEGER          IFAIL, NPTS
*     .. External Functions ..
      DOUBLE PRECISION FA, FB, P1, P2A, P2B
      EXTERNAL         FA, FB, P1, P2A, P2B
*     .. External Subroutines ..
******************************************************
* EXTERNAL declarations need to be removed.          *
C     EXTERNAL         D01DAF
*                                                    *
******************************************************
*     .. Executable Statements ..
      WRITE (NOUT,*) 'D01DAF Example Program Results'
      YA = 0.0D0
      YB = 1.0D0
      ABSACC = 1.0D-6
      WRITE (NOUT,*)
      WRITE (NOUT,*) 'First formulation'
      IFAIL = 1
*
      CALL D01DAF(YA,YB,P1,P2A,FA,ABSACC,ANS,NPTS,IFAIL)
*
      WRITE (NOUT,99999) 'Integral =', ANS
      WRITE (NOUT,99998) 'Number of function evaluations =', NPTS
      IF (IFAIL.GT.0) WRITE (NOUT,99997) 'IFAIL = ', IFAIL
      WRITE (NOUT,*)
      WRITE (NOUT,*) 'Second formulation'
      IFAIL = 1
*
      CALL D01DAF(YA,YB,P1,P2B,FB,ABSACC,ANS,NPTS,IFAIL)
*
      WRITE (NOUT,99999) 'Integral =', ANS
      WRITE (NOUT,99998) 'Number of function evaluations =', NPTS
      IF (IFAIL.GT.0) WRITE (NOUT,99997) 'IFAIL = ', IFAIL
      STOP
*
99999 FORMAT (1X,A,F9.4)
99998 FORMAT (1X,A,I5)
99997 FORMAT (1X,A,I2)
      END
*
      DOUBLE PRECISION FUNCTION P1(Y)
*     .. Scalar Arguments ..
      DOUBLE PRECISION             Y
*     .. Executable Statements ..
      P1 = 0.0D0
      RETURN
      END
*
      DOUBLE PRECISION FUNCTION P2A(Y)
*     .. Scalar Arguments ..
      DOUBLE PRECISION              Y
*     .. Intrinsic Functions ..
      INTRINSIC                     SQRT
*     .. Executable Statements ..
      P2A = SQRT(1.0D0-Y*Y)
      RETURN
      END
*
      DOUBLE PRECISION FUNCTION FA(X,Y)
*     .. Scalar Arguments ..
      DOUBLE PRECISION             X, Y
*     .. Executable Statements ..
      FA = X + Y
      RETURN
      END
*
      DOUBLE PRECISION FUNCTION P2B(Y)
*****************************************************
* Add USE statements for relevant chapters          *
      USE NAG_F77_X_CHAPTER
*                                                   *
*****************************************************
*     .. Scalar Arguments ..
      DOUBLE PRECISION              Y
*     .. External Functions ..
******************************************************
* Function Type declarations need to be removed.     *
C     DOUBLE PRECISION              X01AAF
*                                                    *
******************************************************
******************************************************
* EXTERNAL declarations need to be removed.          *
C     EXTERNAL                      X01AAF
*                                                    *
******************************************************
*     .. Executable Statements ..
      P2B = 0.5D0*X01AAF(0.0D0)
      RETURN
      END
*
      DOUBLE PRECISION FUNCTION FB(X,Y)
*     .. Scalar Arguments ..
      DOUBLE PRECISION             X, Y
*     .. Intrinsic Functions ..
      INTRINSIC                    COS, SIN
*     .. Executable Statements ..
      FB = Y*Y*(COS(X)+SIN(X))
      RETURN
      END

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

    Many LAPACK routines have a "workspace query" mechanism which allows a caller to interrogate the routine to determine how much workspace to supply. Note that LAPACK routines from the MKL library may require a different amount of workspace than the equivalent NAG versions of these routines. Care should be taken when using the workspace query mechanism.

    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 nag_mkl.lib, nag_mkl_md.lib and FLW6I21DC_mkl.lib to avoid problems with the vendor version:

      DBDSQR    ZBDSQR    DGEBAL    ZGEBAL    DGEEVX    ZGEEVX
    
  2. G02

    The value of ACC, the machine-dependent constant mentioned in several documents in the chapter, is 1.0D-13.
  3. P01

    On hard failure, P01ABF writes the error message to the error message unit specified by X04AAF and then stops.
  4. S07 - S21

    Functions in this chapter will give error messages if called with illegal or unsafe arguments. The constants referred to in the Library Manual have the following values in this implementation:
    S07AAF  F(1)   = 1.0D+13
            F(2)   = 1.0D-14
    
    S10AAF  E(1)   = 1.8500D+1
    S10ABF  E(1)   = 7.080D+2
    S10ACF  E(1)   = 7.080D+2
    
    S13AAF  x(hi)  = 7.083D+2
    S13ACF  x(hi)  = 1.0D+16
    S13ADF  x(hi)  = 1.0D+17
    
    S14AAF  IFAIL  = 1 if X > 1.70D+2
            IFAIL  = 2 if X < -1.70D+2
            IFAIL  = 3 if abs(X) < 2.23D-308
    S14ABF  IFAIL  = 2 if X > 2.55D+305
    
    S15ADF  x(hi)  = 2.66D+1
            x(low) = -6.25D+0
    S15AEF  x(hi)  = 6.25D+0
    
    S17ACF  IFAIL  = 1 if X > 1.0D+16
    S17ADF  IFAIL  = 1 if X > 1.0D+16
            IFAIL  = 3 if 0.0D+00 < X <= 2.23D-308
    S17AEF  IFAIL  = 1 if abs(X) > 1.0D+16
    S17AFF  IFAIL  = 1 if abs(X) > 1.0D+16
    S17AGF  IFAIL  = 1 if X > 1.038D+2
            IFAIL  = 2 if X < -5.6D+10
    S17AHF  IFAIL  = 1 if X > 1.041D+2
            IFAIL  = 2 if X < -5.6D+10
    S17AJF  IFAIL  = 1 if X > 1.041D+2
            IFAIL  = 2 if X < -1.8D+9
    S17AKF  IFAIL  = 1 if X > 1.041D+2
            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) > 7.00D+2
            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 0.0D+00 < X <= 2.23D-308
    S18AEF  IFAIL  = 1 if abs(X) > 7.116D+2
    S18AFF  IFAIL  = 1 if abs(X) > 7.116D+2
    S18CDF  IFAIL  = 2 if 0.0D+00 < X <= 2.23D-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) > 7.00D+2
            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) >= 4.95000D+1
    S19ABF  IFAIL  = 1 if abs(x) >= 4.95000D+1
    S19ACF  IFAIL  = 1 if X > 9.9726D+2
    S19ADF  IFAIL  = 1 if X > 9.9726D+2
    
    S21BCF  IFAIL  = 3 if an argument < 1.579D-205
            IFAIL  = 4 if an argument >= 3.774D+202
    S21BDF  IFAIL  = 3 if an argument < 2.820D-103
            IFAIL  = 4 if an argument >= 1.404D+102
    
  5. X01

    The values of the mathematical constants are:
    X01AAF (PI)    = 3.1415926535897932D+00
    X01ABF (GAMMA) = 0.5772156649015329D+00
    
  6. X02

    The values of the machine constants are:

    The basic parameters of the model

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

    Derived parameters of the floating-point arithmetic

    X02AJF = 1.11022302462516D-16
    X02AKF = 2.22507385850721D-308
    X02ALF = 1.79769313486231D+308
    X02AMF = 2.22507385850721D-308
    X02ANF = 2.22507385850721D-308
    

    Parameters of other aspects of the computing environment

    X02AHF = 1.42724769270596D+45
    X02BBF = 2147483647
    X02BEF = 15
    X02DAF = .FALSE.
    
  7. X04

    The default output units for error and advisory messages for those routines which can produce explicit output are both Fortran Unit 6.

    5. Documentation

    The Library Manual is supplied in the form of Portable Document Format (PDF) files, with an HTML index, in the manual folder (either installed locally or on the distribution CD). The introductory material is also provided as HTML files in the manual folder.

    A main index file has been provided (manual\html\mark21.html) which contains a fully linked contents document pointing to all the available PDF (and where available HTML) files. This index file is available from the Start Menu under

      Start|All Programs|NAG|FL21|NAG Fortran Library Manual
    
    by default. Use your HTML browser to navigate from here.

    In addition the following are provided:

    This is available from the Start Menu under
      Start|All Programs|NAG|FL21|NAG Fortran Library -
          Intel Visual Fortran compiler (FLW6I21DCL). Users' Note
    
    by default.

    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 (in this case FLW6I21DCL).

    (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 that 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 any of the NAG Response Centres (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