Currently, vtd can run under

Linux
HP-UX 9, 10 and 11
SunOS

	I. Dependencies.
        ----------------

1) Fortran 90 compiler. 
   Supported compilers: gfortran 4.3.0 or newer and
                        Intel Fortran under Linux compiler 9.1 or newer,
                        HP-UX Fortran compiler 2.4 or newer
                        Sun f90 compiler.

2) C compiler;

3) BLAS. (Basic Linear Algebra Software). It can be either a vendor supplied 
          library or ATLAS. ( http://math-atlas.sourceforge.net/ )

4) petools. ( http://gemini.gsfc.nasa.gov/petools/ )

5) cfitsio (optionally). Refer to 
   http://heasarc.gsfc.nasa.gov/docs/software/fitsio/fitsio.html

5) gmake


	II. Compile and link.
        ---------------------


./configure
gmake
gmake install

  By default binary files are put in $HOME/bin and data files needed for
vtd are put in $HOME/share . Option --prefix= changes it. If configure 
does not find petools library, you need to specify the name of the 
library with full path explicitly using option --with-petools. 
Distribution kit contains also data files needed for computation of
path delay. By default these files are installed in $HOME/share/vtd
You can override these default with option --data.

Example:

./configure --prefix=/opt --with-petools=/opt --data=/data/vtd
            --with-cfitsio=/opt

  Complete list of configure options can be printed by ./configure --help

  The package VTD can be compiled with or without support of cfitsio
library for reading files in FITS-format. If the library VTD is compiled
without cfitsio support, it will not be able to compute and apply 
contribution caused by source structure.



	III. Post installation.
        -----------------------


  If you intend to use vtd you should apply definitions of environment
variables listed in file vtd_vars which was put in ${prefix}/bin 
directory, where ${prefix} is the name of the root directory which you have 
specified with option --with-prefix, or $HOME if you did not use this option.
Under tcsh or csh execute a command:

source ${prefix}/bin/vtd_vars

 It is a good idea to include this line in you shell startup command file.


	IV. Usage.
        ----------

  It is assumed you sourced ${prefix}/bin/vtd_vars with definitions of 
environment variables used by VTD. Include files related to vtd are in 
$VTD_INC directory, vtd library can be found in $VTD_LIB/libvtd.a, an 
example is $VTD_BIN/example_vtd_01, data files are in $VTD_DATA. 
When you compile your application against vtd, you should specify these 
libraries in the makefile:

LIBS 	=				\
          (... your libraries ...)      \
	$(VTD_LIB)/libvtd.a 		\
	$(VTD_CFITSIO_LIB)/libcfitsio.a \
	$(PETOOLS_LIB)/pet_util.a 	\
	$(PETOOLS_LIB)/matvec.a 	\
	$(PETOOLS_LIB)/diagi.a 		\
	$(PETOOLS_LIB)/libpgplot.a 	\
	$(SOLVE_LIB_X11)		\
	$(SOLVE_LIB_XT)			\
	$(SOLVE_LIB_XHP11)		\
        $(SOLVE_LIB_VEC)		\
	$(SOLVE_LIB_BLAS) 		\
	$(SOLVE_EXTRA_LIB) 

  NB: some compilers by default insert trailing underscores to global
variables. VTD is compiled **without trailing underscores**. You should
disable this inserting trailing underscores.

  Recommended lines in makefiles for compilation of VTD-compatible 
applications:

.f.o:
	$(MK5_F95) -I$(VTD_INC) -c -o $*.o $*.f  

	$(MK5_F95_OPT) -I$(VTD_INC) -c -o $*.o $*.f  

  The environment variables above are defined in file 
${prefix}/bin/vtd_vars where ${prifix} is the name of the 
directory where VTD is installed.

Refer to example/vtd_test_01.mak makefile