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
We also assume that the default shortcut for the command prompt
is placed in the Start Menu under:
Start|Programs|NAG|FL21|
If this shortcut does not exist, please consult with the system manager (or the person who did the installation).
The shortcut:
Start|Programs|NAG|FL21|NAG Fortran Library - Lahey-Fujitsu Fortran compiler. 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.
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\flw3221dll\batch\envvars.bat"
If the file is not in the default location, you can locate it
by searching for the file envvars.bat containing flw3221dll.
You may then compile and link to the NAG Fortran Library on the command line using one of the following commands:
lf95 driver.f nag_lah.lib -blas -lapack lf95 driver.f nag_nag.libwhere driver.f is your application program. The order of the libraries in the first command is important because certain parts of the the Lahey LAPACK should not be used (see b. in Section 4).
The first command will use the library without the NAG version of the BLAS/LAPACK procedures nag_lah.lib and the Lahey BLAS/LAPACK while the second will use the library with the NAG version of the BLAS/LAPACK procedures nag_nag.lib.
In this case we recommend that you read the relevant sections of the Lahey/Fujitsu Fortran Enterprise Edition manual.
Please note that 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. If you work in Debug mode, you may receive a warning message about conflicting C runtime libraries. This is usually harmless.
The batch files need the environment variable NAG_FLW3221DLL.
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_FLW3221DLL.
This shortcut is placed in the Start Menu under
Start|Programs|NAG|FL21|NAG Fortran Library - Lahey-Fujitsu Fortran compiler. 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\flw3221dll\batch\envvars.bat"
If the file is not in the default location, you can locate it
by searching for the file envvars.bat containing flw3221dll.
nag_example_lah.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_lah.lib and the Lahey BLAS/LAPACK. Finally, the executable program will be run. The example program concerned is specified by the argument to nag_example_lah.bat, e.g.
nag_example_lah e04ucfwill copy the example program and its data into the files e04ucfe.f and e04ucfe.d in the current folder and process them to produce the example program results in the file e04ucfe.r.
Alternatively you could use:
nag_example e04ucf
The difference between nag_example_lah.bat and nag_example.bat is that while nag_example_lah.bat uses the library nag_lah.lib and the Lahey BLAS/LAPACK, nag_example.bat uses the self-contained library nag_nag.lib.
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 library nag_nag.lib, (using the NAG BLAS and LAPACK routines). Running the examples with vendor BLAS or LAPACK may give slightly different results.
double precision - DOUBLE PRECISION (REAL*8)
basic precision - double precision
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 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.
(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_chapterThese are supplied in pre-compiled form (.mod files) and they can be accessed by specifying the -mod pathname option on each lf95 invocation, where pathname (C:\Program Files\NAG\FL21\flw3221dll\nag_interface_blocks) is the location of the folder containing the compiled interface blocks.
Alternatively, you can add the following line to the configuration file LF95.FIG
-mod .;"C:\Program Files\NAG\FL21\flw3221dll\nag_interface_blocks"
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
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 library nag_lah.lib to avoid problems with the vendor version:
ZHPEVD ZHEEVR ZGGESX ZGESDD
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) = 2.2D+15
S13ADF x(hi) = 2.2D+15
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 > 2.2D+15
S17ADF IFAIL = 1 if X > 2.2D+15
IFAIL = 3 if 0.0D+00 < X <= 2.23D-308
S17AEF IFAIL = 1 if abs(X) > 2.2D+15
S17AFF IFAIL = 1 if abs(X) > 2.2D+15
S17AGF IFAIL = 1 if X > 1.038D+2
IFAIL = 2 if X < -2.2D+10
S17AHF IFAIL = 1 if X > 1.041D+2
IFAIL = 2 if X < -2.2D+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
X01AAF (PI) = 3.1415926535897932D+00 X01ABF (GAMMA) = 0.5772156649015329D+00
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 = 2.25179981368524D+15 X02BBF = 2147483647 X02BEF = 15 X02DAF = .FALSE.
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, 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. Use your HTML browser to navigate from here.
In addition the following are provided:
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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 FLW3221DLL).
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