Notes on Using Numerical Recipes in C
with Various Windows Compilers


USING THE NUMERICAL RECIPES IN C WITH THE BORLAND 
C++ BUILDER VISUAL ENVIRONMENT

Let's assume that you have installed the C Recipes in
a directory that we will refer to symbolically as CDIR.
Typically CDIR will be something like "C:\numrec\c.210\ansi",
and this directory will contain the subdirectories
"recipes", "examples", "other" and "data".  In the instructions
below, you will need to substitute you actual installation
directory path wherever we have written CDIR.

We consider the case in which you are going to write a 
program than uses the Numerical Recipe named svdcmp.c.  
In this example, we use the Numerical Recipes Example Routine
named xsvdcmp.c as our program, since it is a typical
program making use of svdcmp.c.  This program may be found
in the "examples" subdirectory of the installation directory.

There are several ways in which to use your compiler to
prepare an executable program.  We are just detailing one of 
the possibilities, one that we have found convenient.

1. First, create a working directory named "xsvdcmp" as
a subdirectory of CDIR.  (You may name the subdirectory
anything you like and locate it in some other place.
However, we have chosen the name xsvdcmp because 
that is the name of the program we will prepare, and we have
chosen the CDIR location to keep the pathnames short in
our example.)

2. Into this working directory, copy the files that will
be necessary for the project.  These files include:

CDIR\examples\xsvdcmp.c
CDIR\recipes\svdcmp.c
CDIR\recipes\pythag.c
CDIR\other\nrutil.c
CDIR\data\matrx3.dat

Routine xsvdcmp.c is the main program.  It calls svdcmp(),
which, in turn, makes calls to pythag().  The file nrutil.c is a
file of Numerical Recipes utility functions that are used by
many of the Recipes and Example Programs. The data file 
matrx3.dat is a file containing  test matrices, and is 
used by xsvdcmp.c as a source of input data.

(Note that it is not actually essential that the source files 
xsvdcmp.c, svdcmp.c, pythag.c and nrutil.cbe copied into
a working directory.  They could be compiled in their
original location.  However, in some cases you will want
to modify the Numerical Recipes codes to suit your own
applications, and collecting the codes into a working
directory is a way of ensuring that the changes you make
do not affect any of your other projects.)

3. Start up the C++ Builder visual programming environment.

4. Make the menu selection "File/New.../Console Wizard".  
Our notation here is meant to indicate that you click on the
"File" menu item, then select "New..." from the drop-down
list, and finally select "Console Wizard" from the panel of
options that appears.

In the "Console Wizard" setup box, select:
	Window Type: Console
	Execution Type: EXE
Then click on "Finish".

5. This will produce a project window with a generic program
name something like  "Project1.c".  We will next name our 
project "p_xsvdcmp" and generate a program named 
"p_svdcmp.cpp" by the following procedure:

6. Make the menu selection "File/Save Project As ..."

Use the file-selection dialogue box that comes up to navigate the the 
directory CDIR\xsvdcmp\ and save the project as "p_svdcmp.bpr".  
(Again, you could name it anything you like, but stay with this for 
now.)  The program window will now have the title p_svdcmp.cpp, 
and will have contents something like this:


	#pragma hdrstop
	#include 

	//---------------------------------------
	#pragma argsused
	int main(int argc, char* argv[])
	{
	        return 0;
	}
 

This bit of code framework is provided compliments of the
vendor.  It can be turned into a workable C program by filling
in the routine "main()" with whatever programming instructions
you want to carry out.  Presumably, one of these instructions will
involve a call to the routine svdcmp.c, since that is the point
of this exercise.

7. In the present case, for example, we could judiciously copy
the contents of the program xsvdcmp.c into this file, putting
the "include" statements near the top and the function "main()" 
of xsvdcmp.c in place of the one-line "main()" routine that has 
been automatically provided.  This, however, leaves some 
Borland-specific statements (particularly, the one about 
"condefs.h") in the program, and makes it less portable.  We 
generally try to isolate  vendor-specific code into a separate 
file, and the following steps show how to do that.

8. Erase the code that has been provided, and replace it with 
the two statements:

	#include 
	#define main

9. Add the necessary files to your project, using the menu 
selection "Project/Add to Project" to navigate to and select 
each of the source code files that has been copied into the 
working directory:

	CDIR\xsvdcmp\xsvdcmp.c
	CDIR\xsvdcmp\svdcmp.c
	CDIR\xsvdcmp\pythag.c
	CDIR\xsvdcmp\nrutil.c

10. Your main project source code p_svdcmp.cpp will then 
read:

	#include 
	USEUNIT("xsvdcmp.c");
	USEUNIT("svdcmp.c");
	USEUNIT("pythag.c");
	USEUNIT("nrutil.c");
	#define main

11.  There is one more issue.  Program xsvdcmp.c has 
include-statements that will try to include "nr.h" and
"nrutil.h", which it will look for in the working directory 
"CDIR\xsvdcmp".  The actual location of these files is the 
"other" subdirectory of the Numerical Recipes installation
directory. There are at least two solutions to this problem:

     a. Use the menu selection "Project/Options/
     Directories/Conditionals", and add the text "..\other;" 
     to the beginning of the include path.

     OR

     b. Create a file named "nr.h" in the working directory,
     and in this file place the single line:  #include "..\other\nr.h".
     Do the same for "nrutil.h".  Then when you include these 
     files, they will in turn include the corresponding files in the 
     "CDIR\other" directory.

The virtue of either method is that your installation will have 
only single bona-fide "nr.h" and "nrutil.h" files (the ones in the 
"CDIR\other" directory), rather than having copies in multiple 
locations.  Therefore, if you ever want to upgrade to a new 
version, or make a correction to this file, you only need to 
edit a single file.  

12. Now it is time to compile.  Just choose the menu selection
"Project/Build p_svdcmp", wait for all the compilation and 
linking to take place.  If there are any error messages 
(other than innocuous compiler warnings), you will need to do 
some debugging.

13. You may now run the program with the menu selection 
"Run/Run", and witness the program output in the console 
window that appears. 

14. There is one final wrinkle.  The "xsvdcmp.c" program 
reads in several matrices, one-by-one, and pauses between 
each case so that you can see the output.  Some of the 
Numerical Recipes Example Routines, on the other hand, 
have the property that they just do a calculation, print some 
output, and then terminate.  

Unfortunately, under Borland C++ Builder, the completion 
of a console application causes the console window to 
close immediately, with the result that you get only a brief 
glimpse at the data you have  computed.

The solution to this problem is to create a file named 
nrexit.c with the following contents:

	#include 
	using namespace std;

	// Function used to stall exit in Borland C++ Builder

	void nrexit(void)
	{
	        cin.get();
	        return;
	}

	#pragma exit nrexit

If you add this source file to your project along with the main
routine and recipes, then you will find that upon completing your 
program, the system will leave the console window open until 
you press a key on the keyboard.


USING THE NUMERICAL RECIPES IN C WITH BORLAND 
C++ BUILDER FROM A DOS COMMAND LINE

It is also possible use the Borland C++ Builder compiler to 
compile and link Numerical Recipes programs from a DOS 
command line.  In doing so, you give up the great advantages 
of the integrated visual programming environment.  However, 
you gain the ability to embed your compilation instructions into 
scripts or makefiles.

As above, we assume that the C Recipes are installed in a
directory that we shall refer to symbolically as CDIR.  In this 
directory there are subdirectories "recipes" containing the 
Numerical Recipes, "examples" containing the Numerical 
Recipes Example Routines, "other" containing the utility 
routines, and "data" containing data files for testing.  In all 
of the instructions below, you will need to change the symbol 
CDIR to the actual path of this installation directory.

We consider the case that you are going to write a 
program than uses the Numerical Recipe named svdcmp.c.  
In this example, we use the Numerical Recipes Example Routine
named xsvdcmp.c as our program, since it is a typical
program making use of svdcmp.c.  This program may be found
in the "examples" subdirectory of CDIR.

1. First, create a working directory named "xsvdcmp" as a 
subdirectory of CDIR

> mkdir xsvdcmp

2. Move into this subdirectory

> cd xsvdcmp

3. Move the necessary files into the working directory

> copy ..\examples\xsvdcmp.c
> copy ..\recipes\svdcmp.c
> copy ..\recipes\pythag.c
> copy ..\other\nrutil.c
> copy ..\data\matrx3.dat

Routine xsvdcmp.c is the main program.  It calls svdcmp(),
which, in turn, makes calls to pythag().  The file nrutil.c is a
file of Numerical Recipes utility functions that are used by
many of the Recipes and Example Programs.  The data file 
matrx3.dat is a file containing  test matrices, and is used by
xsvdcmp.c as a source of input data.

4. The header files "nr.h" and "nrutil.h" are also needed.  

You could copy these from the directory "CDIR\other".  We 
suggest instead that you create a file named "nr.h" and put
in this file the single line

#include "..\other\nr.h"

Do a similar thing for "nrutil.h".  Then when you include these 
files, they will in turn include the corresponding files in the 
"CDIR\other" directory.

The virtue of this method is that your installation will have only one
bona-fide include file (the one in the "other" directory), rather than 
having copies in multiple locations.  Therefore, if you ever want
to upgrade to new versions, or to make corrections, you only
need to modify the master file.  

5. Next, compile each of the source files, producing a corresponding
object file .obj for each one:

> bcc32 -c -w- -Od xsvdcmp.c
> bcc32 -c -w- -Od svdcmp.c
> bcc32 -c -w- -Od pythag.c
> bcc32 -c -2- -Od nrutil.c

The first of these commands, for example, compiles the source
file xsvdcmp.c and produces the object file xsvdcmp.obj.

6. Then link all of the object files to produce an executable 
named "xsvdcmp.exe".

> ILINK32 /ap /w- /x /C xsvdcmp.obj svdcmp.obj pythag.obj nrutil.obj
     c0x32.obj cw32.lib import32.lib

(This command should be a single line.)

The first four object files on this line are object files
produced in the previous step.  The following object file and
libraries are compiler-related and should just be
added routinely to your link commands.

7. Following the linking operation, you may run the executable:

> xsvdcmp



USING THE NUMERICAL RECIPES IN C WITH THE 
MICROSOFT VISUAL C++ DEVELOPMENT ENVIRONMENT

Let's assume that the C Recipes have been installed in a
directory that we shall refer to symbolically as CDIR.  In this 
directory there are subdirectories "recipes" containing the 
Numerical Recipes, "examples" containing the Numerical 
Recipes Example Routines, "other" containing the utilities, 
and "data" containing data files for testing.  You will need to 
change any references to the symbol CDIR below to the actual 
name of the directory in which these subdirectories are located.

We shall consider the case that you are going to write a 
program than uses the Numerical Recipe named svdcmp.c.  
In this example, we use the Numerical Recipes Example Routine
named xsvdcmp.c as our program, since it is a typical
program making use of svdcmp.c.  This program may be found
in the "examples" subdirectory of CDIR.

There are several ways in which to use your compiler to
prepare the executable program. We are just detailing one of 
the possibilities, one that we have found convenient.

1. First, create a working directory named "xsvdcmp" as
a subdirectory of CDIR. ( You may name the subdirectory
anything you like and locate it in some other place. 
However, we have chosen the name xsvdcmp because 
that is the name of the program we will prepare, and we have
chosen the CDIR location to keep the pathnames short in
our example.)

2. Into this working directory, copy the files that will
be necessary for the project.  These files include:

CDIR\examples\xsvdcmp.c
CDIR\sources\svdcmp.c
CDIR\sources\pythag.c
CDIR\other\nrutil.c
CDIR\data\matrx3.dat

Routine xsvdcmp.c is the main program.  It calls svdcmp(),
which, in turn, makes calls to pythag().  The data file 
matrx3.dat is a file containing test matrices, and is  used 
by xsvdcmp.c as a source of input data.

(Note that it is not actually essential that the source
files xsvdcmp.c, svdcmp.c and pythag.c be copied into
a working directory.  They could be compiled in their
original location.  However, in some cases you will want
to modify the Numerical Recipes codes to suit your own
applications, and collecting the codes into a working
directory is a way of ensuring that the changes you make
do not affect any of your other projects.)

3. Start up the Visual C++ programming environment.

4. Make the menu selection "File/New/Win32 Console Application"
Our notation here is meant to indicate that you click on the "File" 
menu item, then select "New..." from the drop-down list, and finally 
select "Win32 Console Application" from the panel of options that 
appears.  You will also need to fill in this information in the panel:

	Project Name: xsvdcmp
	Location: CDIR\xsvdcmp
	"Create new workspace" should be checked

In the "Location:" entry, you should replace the symbol CDIR by 
the actual path name of the directory in which the xsvdcmp 
subdirectory has been created.

Click OK and you will then be asked "What kind of Console 
Application?". The answer is "Empty Project"

You will then be shown a summary of your choices. Click on OK.

5. Next add the necessary source code files to your project.

     Select "Project/Add to Project/Files"
     Use file selector to select each of the souce code files 
     in the working directory: xsvdcmp.c, svdcmp.c, 
     pythag.c and nrutil.c

6.   There is one more issue.  Program xsvdcmp.c has 
include-statements that will try to include "nr.h" and
"nrutil.h", which it will look for in the working directory 
"CDIR\xsvdcmp".  The actual location of these files is the 
"CDIR\other" subdirectory of the Numerical Recipes installation
directory. There are at least two solutions to this problem:

     a. Use the menu selection "Project/Settings/C-C++".
     Under "Category", select "Preprocessor", and then in
    the "Additional include directories" box, insert "..\other"

     OR

     b. Create a file named "nr.h" in the working directory,
     and in this file place the single line:  #include "..\other\nr.h".
     Do the same for "nrutil.h".

The virtue of either method is that your installation will have 
only single bona-fide "nr.h" and "nrutil.h" files (the ones in the 
"CDIR\other" directory), rather than having copies in multiple 
locations.  Therefore, if you ever want to upgrade to a new 
version, or make a correction to this file, you only need to 
edit a single file.  

7. Then compile and link the program with the menu selection
"Build/Build xsvdcmp.exe".  If there are any errors reported you
will need to do some debugging. 

8. Run the program by selecting "Build/Execute xsvdcmp.exe"
from the menu.



USING THE NUMERICAL RECIPES IN C WITH MICROSOFT 
VISUAL C++ FROM A DOS COMMAND LINE

It is also possible use the Microsoft Visual C++ compiler to 
compile and link Numerical Recipes programs from a DOS 
command line.  In doing so, you give up the great advantages 
of the integrated visual programming environment.  However,
you gain the ability to embed your compilation instructions into
scripts or makefiles.

As above, we assume that the C Recipes are installed in a
directory that we shall refer to symbolically as CDIR.  In this 
directory there are subdirectories "recipes" containing the 
Numerical Recipes, "examples" containing the Numerical 
Recipes Example Routines, "other" containing the utility routines,
and "data" containing data files for testing.  In all of the instructions 
below, you will need to change the symbol CDIR to the actual path 
of this installation directory.

We shall consider the case that you are going to write a 
program than uses the Numerical Recipe named svdcmp.c.  
In this example, we use the Numerical Recipes Example Routine
named xsvdcmp.c as our program, since it is a typical
program making use of svdcmp.c.  This program may be found
in the "examples" subdirectory in the Numerical Recipes 
installation.

1. First, create a working directory named "xsvdcmp" as
a subdirectory of CDIR

> mkdir xsvdcmp

2. Move into that subdirectory

> cd xsvdcmp

3. Move the necessary files into your working directory

> copy ..\examples\xsvdcmp.c
> copy ..\recipes\svdcmp.c
> copy ..\recipes\pythag.c
> copy ..\other\nrutil.c
> copy ..\data\matrx3.dat

Routine xsvdcmp.c is the main program.  It calls svdcmp,
which, in turn, makes a call to pythag.  The file nrutil.c is a
file of Numerical Recipes utility functions that are used by
many of the Recipes and Example Programs.  The data 
file matrx3.dat is a file containing test matrices, and is used 
by xsvdcmp.c as a source of input data.

4. The header files "nr.h" and "nrutil.h" are also needed.  
You may copy them from the directory "CDIR\other".  We 
suggest instead that you create a file named "nr.h" and in 
this file put the single line

#include "..\other\nr.h"

Do the same for "nrutil.h". Then when you include these 
files,  the will in turn include the corresponding files in the 
"CDIR\other" directory.

The virtue of either method is that your installation will have only
single bona-fide include files "nr.h" and "nrutil.h" (the ones in 
the "CDIR\other" directory), rather than having copies in 
multiple locations.  Therefore, if you ever want to upgrade to 
new versions, or to make corrections, you only need to modify 
the master file.  

5. Next, compile each of the source files, producing a 
corresponding object file .obj for each one.

> CL /c /w xsvdcmp.c
> CL /c /w svdcmp.c
> CL /c /w pythag.c
> CL /c /w nrutil.c

The compile command used here assumes that the 
environment variables PATH and INCLUDE have been 
properly set, so that the compiler, include files and libraries 
can be found.  (When you install Visual C++, the setup 
creates a batch file,  VCVARS32.BAT, containing 
commands to modify the PATH,  LIB, and INCLUDE 
environment variables. If these variables haven't been 
set properly, run VCVARS32.BAT before you compile 
at the command prompt. VCVARS32.BAT is located 
in the \bin subdirectory of the Visual C++ installation. 

6. Link all of the object files to produce an executable 
named "xsvdcmp.exe".

> LINK xsvdcmp.obj svdcmp.obj pythag.obj nrutil.obj

(This command assumes that the LIB environment variable is
properly defined.  See the note above about VCVARS32.BAT.)
The four object files on this line are object files produced in 
the previous step. If there are any error messages
issued, then you will need to do some debugging before
continuing.

7. Following the linking operation, you may run the executable:

> xsvdcmp

We have described compiling and linking as a two-step
operation.  In fact, it is common to do both in a single step.
See your compiler manual for details.