Unfortunately compiling this module is not straight forward. The
following are some things to check if you have problems compiling
or running.

*PGPLOT PATCH*

- Is perlTk installed? 

- Is PTK_INCL set correctly in the appropriate .conf file?

    The correct value should be found automatically by the .conf
    file but it may make a mistake (such as using the wrong version
    of perl). Try directly entering the value of PTK_INCL, or using
    the simple one liner. Note that some Linux distributions don't
    install Tk in the site_perl directory, so you will have to hunt
    around for the pTk directory by hand.

- If compiling on Linux you must compile pgplot using g77_gcc.conf 
  NOT g77_aout.conf

- If you are using Tk800.022, you need to define -DOLDTK in the .conf file

- If you a compilation warning like 
    ptkpgplot.c:613: warning: implicit declaration of function `LangWidgetObj'
  then you are compiling for the wrong versipn of Tk. See PGPLOT.patch

*Tk::Pgplot*

- Is Makefile.PL configured correctly?
  If $PGPLOT_DIR cannot be used to locate the pgplot directories and
  include files you must set PGPLOT_INC_LOCATION and PGPLOT_LIB_LOCATION
  in Makefile.PL

- If Makefile.PL cannot find ptkpgplot.h check the value of 
  PGPLOT_INC_LOCATION.

- If Makefile.PL cannot find libptkpgplot.a check the value of 
  PGPLOT_LIB_LOCATION.

- If "make test" fails with something like "undefined symbol: LangWidgetObj"
  then you have compiled pgplot for the wrong Tk version. See PGPLOT.patch

- Is Tk.pm installed? 
  This module has been developed using Tk800.022. Some earlier versions
  before 800.015 are known to not be compatible.

- Is PGPLOT.pm installed? 
   You also need ExtUtils::F77, which PGPLOT.pm also requires.

- Is Makefile.PL really linking you with the correct version of Pgplot?
  If you are using a private version of pgplot with the ptk patch, make
  sure you really are linking with it. I had problems with on HP-UX when
  a -L/usr/local/lib was inserted as the first of the ld options. 
  (I only fixed this by editing the Makefile Makefile.PL produced). You can 
   also do a check using something like:
     > find . -name Pgplot.so -exec ldd \{} \;

- Have you recompiled pgperl since you patch pgplot

- Have you upgrated Tk since you compiled pgplot

