FSPAK with METIS ordering 
I. Misztal, Sept 9, 2005

FSPAK uses a multiple minimum degree ordering. Ducrocq and Druet (EEAP 2003)
and Karin Meyer (AAABG 2005) found that using a multilevel nested 
dissection procedure can reduce the ordering time five times or more, memory by 20-30%,
and factorization/inversion 2-3 times. That procedure is available in a package 
called METIS. Despite being written in C, this package has design to easily 
interface with Fortran.

Karin Meyer gave me her modifications to use METIS in FSPAK. I reworked them so
that they easily fit into this library. In tests, ordering with METIS is much 
faster, however, for some models memory and computing expenses may actually increase.
According to Karin Meyer, the improvement with METIS is best seen in larger models 
with a complicated contemporary structure. 


Installation under Linux (and probably Unix) 
--------------------------------------------------------------
This part applies if metis is installed as part of fspak90.f90
with the entire distribution of F90 programs (progs.f90.gz)
--------------------------------------------------------------

1. Save package metis.tar.gz to directory libs

2. Unpack it in the libs directory by:
    	tar xzvf metis.tar.gz

3. Go to metis directory and compile:
	cd metis-4.0
	make

4. If the compilation ends with an error message, redo it:
	make clean
	make

5. In libs directory,save the original version of fspak and copy the modification:
	mv fspak.f fspak.f.orig
	cp fspak-metis.f fspak.f

6. Modify a section in Makefile to create the sparsem.a library:
	ar cr sparsem.a kind.o sparse.o sparse2.o fspak90.o \
       	    fspak.o fspaksub.o sparssub.o pcg.o second.o \
       	    metis-4.0/Lib/*.o

7. Recompile:
	make

-----------------------------------------------------------
This part applies if METIS is installed with fspak.f alone
-----------------------------------------------------------

a. Save package metis.tar.gz to a directory where fspak.f is located

b. Do steps 2-5 as above 

c. When linking, include METIS object files:
       	f90 .... metis-4.0/Lib/*.o


Once METIS is installed, fspak can be use to use either the original or the 
new ordering by changing the value of the metis variable. 

METIS has been effortlessly installed in RedHat Fedora. There were some problems
with RedHat 9.0 (see point 4 above). There were errors with lack of some libraries
in SUSE 6.2.