NAG C Library, Mark 8

CLW3208DBL, License Managed

Windows XP/Vista Microsoft C/C++

Users' Note


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

In this section we assume that the Library has been installed in the default folder:
  C:\Program Files\NAG\CL08\clw3208dbl
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|CL08
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 installation procedure offers the option of setting the PATH, LIB and INCLUDE global environment variables, in which case the NAG C Library and batch files will be accessible from the Command Prompt without any further action.

Otherwise the shortcut:

  Start|All Programs|NAG|CL08|NAG C Library - 
      Microsoft C++ (CLW3208DBL). 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, supplied MKL and Microsoft C++. The environment variable NAG_CLW3208DBL, which is needed by the nagc_example_*.bat batch files is also set.

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 for this file is:

  C:\Program Files\NAG\CL08\clw3208dbl\batch\envvars.bat
If this file is not in the default location, you can locate it by searching for the file envvars.bat containing clw3208dbl.

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

cl /MT driver.c nagc_mkl_MT.lib mkl_s.lib libguide.lib
cl /MT driver.c nagc_nag_MT.lib
cl /MD driver.c CLW3208DB_mkl.lib
cl /MD driver.c CLW3208DB_nag.lib
cl /MD driver.c nagc_nag_MD.lib
where driver.c is your application program.

The Microsoft C/C++ options:

means compile code to link with LIBCMT.LIB, the static multi-threaded version of the C run time library
means compile code to link with MSVCRT.LIB, the import library for the multi-threaded DLL version of the C run time library
These options should be used consistently throughout your project.

nagc_mkl_MT.lib is a static library that does not include BLAS/LAPACK and should be linked to the MKL static libraries. nagc_nag_MT.lib is a static library that includes NAG BLAS/LAPACK. Both libraries have been compiled with the /MT option. This option must be used when compiling applications to be linked with either of these libraries to ensure linking to the correct C run time libraries.

CLW3208DB_mkl.lib is a DLL import library that does not include NAG BLAS/LAPACK and links to the DLL version of MKL. CLW3208DB_nag.lib is a DLL import library that includes NAG BLAS/LAPACK. Both libraries have been compiled with the /MD option. This option must be used when compiling applications to be linked with either of these libraries to ensure linking to the correct C run time libraries.

nagc_nag_MD.lib is an alternative version of the static library that includes NAG BLAS/LAPACK and is compiled with the /MD option. It is provided for applications which require the multi-threaded DLL C run time library to be used. For example if, in addition to the static NAG C Library, you link your code with another library that is compiled with /MD, you should compile your code with the /MD option and link with nagc_nag_MD.lib. There is not an MKL version of this library as there is no compatible MKL static library.

Note 1
The Microsoft C Release 8.0 link command may generate warning messages for deprecated features when linking the MKL 8.0 static libraries. These warnings may safely be ignored.
Note 2
The Microsoft C Version 8.0 run time library DLLs are installed in the bin folder, allowing these NAG C Library DLLs to be used in environments where Microsoft C Version 8.0 is not installed.

3.1.2. From MS Visual Studio

If it is planned to use Microsoft Visual Studio to build programs that use the NAG C Library, each user should set the appropriate options. Start Visual Studio and from the "Tools" menu, select "Options" and expand the "Projects and Solutions" section and click the "VC++ Directories" entry. Using the "Show directories for" menu, The default folders are as follows:
  "Include Files"
    "C:\Program Files\NAG\CL08\clw3208dbl\include"
  "Library Files"
    "C:\Program Files\NAG\CL08\clw3208dbl\lib"
    "C:\Program Files\NAG\CL08\clw3208dbl\MKL_ia32_8.0\lib"
  "Executable Files"
    "C:\Program Files\NAG\CL08\clw3208dbl\bin"
    "C:\Program Files\NAG\CL08\clw3208dbl\MKL_ia32_8.0\bin"

The NAG C Library (and possibly the MKL libraries) need to be specified in the linker options. Either, right click the project name and select "Properties", or select your project and click the "Project" menu button and select "Properties". Expand "Configuration Properties", select "Linker" and then "Select Input". Add the appropriate library files to the "Additional Dependencies"; please see the table below.

Additionally the appropriate C run time library option needs to be set. First add your C file, e.g. NAG example program, to the project, using the "Project" menu and "Add Existing Item". (If you don't have a C file in the project, you won't see the C++ options.) Either, right click the project name and select "Properties", or select your project and click the "Project" menu button and select "Properties". Expand "Configuration Properties" (if required), expand C/C++ and select "Code Generation". Then select "Run Time Library" and change this to the appropriate version.

NAG C Library MKL Libraries C Run time Libraries
nagc_mkl_MT.lib mkl_s.lib libguide.lib    Multi-threaded (/MT)
nagc_nag_MT.lib Multi-threaded (/MT)
CLW3208DB_mkl.lib    Multi-threaded DLL (/MD)
CLW3208DB_nag.lib Multi-threaded DLL (/MD)
nagc_nag_MD.lib Multi-threaded DLL (/MD)

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

The above instructions are specific to Microsoft Visual Studio 2005, if a different version of Visual Studio is being used the procedure will differ slightly.

3.2. Accessibility Check

The diagnostic program NAG_C_DLL_info.exe, which by default is located in C:\Program Files\NAG\CL08\clw3208dbl\diagnostics, may be used to check whether the DLLs CLW3208DB_nag.dll and CLW3208DB_mkl.dll are accessible from the current environment. If this program is started from Windows Explorer or from the
  Start|All Programs|NAG|CL08|NAG C Library -
      (CLW3208DBL). Check Accessibility
shortcut on the Start Menu, the DLLs will be found if the global PATH environment variable has been set to include their location. If it is run from a Command Prompt window, then the environment local to that window will prevail. (See Section 3.1 for more information on environment variables.)

For each of the DLLs that it loads successfully, NAG_C_DLL_info.exe will print the location of the DLL, and pop up a message box showing the implementation details as provided by a call to the routine a00aac. It also calls a00acc to check the availability of a valid license key if required by the implementation and reports if this is not found; "Status OK" indicates that a valid key was either found or not required.

3.3. Example Programs

The example programs are most easily accessed using the batch files nagc_example_static_MT.bat, nagc_example_dll.bat and nagc_example_static_MD.bat, which can be found in the "batch" folder. These batch files 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.

These batch files require that the environment variables for Microsoft C/C++ and the NAG C Library are set. In particular, the environment variable NAG_CLW3208DBL needs to be set to the location of the NAG C Library. Please see Section 3.1.1 for details of how to do this.

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

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

nagc_example_static_MT.bat links with the static library using NAG BLAS/LAPACK compiled with /MT.

To link with the MKL version of the static library compiled with /MT, use the -mkl option, e.g.

  nagc_example_static_MT -mkl d01ajc

The nagc_example_static_MD batch file is used in the same way and links to the the static NAG C Library compiled with /MD, but does not have the -mkl option.

The nagc_example_dll.bat batch file links to the DLL version of the NAG C Library, e.g.

  nagc_example_dll d01ajc
  nagc_example_dll -mkl d01ajc
The first command links with the DLL library using NAG BLAS/LAPACK. To link with the MKL version of the DLL, use the -mkl option, as shown in the second command.

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 nagc_nag_MT.lib (using the NAG BLAS and LAPACK routines). Running the examples with MKL BLAS or LAPACK may give slightly different results.

Please note that with the DLL version of this library, if you are not using Release 8.0 (Version 14.00.50727.42) of the Microsoft Visual C++ compiler, mixing output from your C code with output from NAG C Library functions, e.g. X04 chapter functions, may result in output files where results appear in the wrong order. This is apparent when running the NAG Example Programs, e.g. g02efce.c. This is caused by having two different C run time libraries linked to the executable, using buffered output which is flushed independently by each run time library. The example programs supplied with this implementation have fflush statements added wherever possible in order to minimise the number of such cases. Also code that relies on reading the same input file from C code and also via a NAG C Library function will not work as the current file pointer will not be shared by the two run time libraries. This may be seen in the failure of the NAG C Library Example Program e04nrce.c, which reads data for the C example and options for e04nrc from the same file.

A more detailed description of this problem may be found on the NAG web site at

These problems are not found in the static versions of the NAG C Library.

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, f16, 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 nagc_mkl.lib and CLW3208DB_mkl.dll to avoid problems with the MKL version:

  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:
    (a) Chapter s
    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 = Nag_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 = 1.84467440737095e+19
    X02BBC = 2147483647
    X02BEC = 15

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 manual folder. The introductory material is also provided as HTML files in the manual folder.

A main index file has been provided (manual\html\mark8.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|CL08|NAG C Library Manual
by default. 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 (in this case CLW3208DBL).

(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:, or

(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

(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

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

Wilkinson House
Jordan Hill Road
OXFORD  OX2 8DR                         NAG Ltd Response Centre
United Kingdom                          email:

Tel: +44 (0)1865 511245                 Tel: +44 (0)1865 311744
Fax: +44 (0)1865 310139                 Fax: +44 (0)1865 310139

801 Warrenville Road
Suite 185
Lisle, IL  60532-4332                   NAG Inc Response Center
USA                                     email:

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

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