       This file contains instructions on how to produce and run
       the components of a FORTRAN software package of routines to
       solve finite difference approximations of certain self-adjoint
       elliptic equations in two-dimensional irregular domains.

	Descriptions of the methodology may be found in the article
	'Solvers for self-adjoint elliptic problems in irregular
 	two-dimensional domains' by P.Cummins and G.Vallis
	and in 'A fast semi--direct method for the numerical
	solution of non--separable elliptic equations in
	irregular domains. J. Comp. Phys. 82, 1989, 398--412.
	by A Pares-Sierra and G. Vallis, and references therein.

       The package is distributed as a single file called Solvers.
       To split Solvers into its components the following UNIX
       command should be executed:

                sh < Solvers

       This should produce the following files:

                Readme
                Makefile
                solvers.f
                poiss.f
                linpack.f
                testcapc.f
                testdcapc.f
                testcapcn.f
                testdcapcn.f
                testreccn.f
                testdreccn.f

       To compile and link files and then run executable code, the
       following UNIX command should be issued:

                       make

       The Makefile assumes the user's FORTRAN compiler is invoked
       with f77 and accepts a -O optimizing directive. If this
       is not the case, then the FC and FFLAGS macros in the
       Makefile should be redefined appropriately.

       The output from the execution of the test programs is found
       in the *.out files which are created at execution time.


       To produce executable code for an individual test program,
       a UNIX command such as the following should be issued:

                 make testcapc

       To clean up file space and to delete object and executable
       files, the following UNIX command should be issued:

                 make clean
