To configure this for development testing, you need only create a file
named local.config in this directory and populate it with the
variables that locate the gtkextra distribution. If you have installed
gtkextra (via make install in that distribution's directory), you need
only specify the location of the gtkextra-config executable. From
that, we can determine the location of the header files and the
libraries. 

Alternatively, if you have not installed gtkextra, you will need to
specify the values for the variables GTKEXTRA_LIB_DIR and
GTEXTRA_INCLUDES.  GTKEXTRA_LIB_DIR should be the name of the
directory in which the libgtkextra.so (or .a) file is located.
For example,
 GTKEXTRA_LIB_DIR=-I/home3/duncan/gtkextra-0.99-14/.libs
We take care of adding the necessary flags for linking the library.

GTKEXTRA_INCLUDES should contain the
-I/directory/for/gtkextra/includes so that we can find the file
`gtkextra/gtksheet.h'. Also, you can add any other pre-processor
symbol definitions, etc.
For example,
 GTKEXTRA_INCLUDES=-I/home3/duncan/gtkextra-0.99-14

If you don't install gtextra, or you install it in a non-standard
location, you may have to set the environment variable LD_LIBRARY_PATH
so that when GGobi attempts to load the plugin shared libraries, it
can find all the dependencies.
