Interface METIS graph partition and reorder package with LaGriT. For details of METIS algorithms and descriptions of the third command line argument see:
http://glaros.dtc.umn.edu/gkhome/views/metis

Partition algorithm divides mesh into npartition parts attempting to assign an equal number of graph vertices (nodes or elements) to each partition and also the number of adjacent elements assigned to different processors is minimized. New attributes are created to hold partition information. Node partition number is in inodeprt, element partition number is in ielemprt.

Reorder algorithm computes a permutation vector, iperm, and an inverse permutation vector, invperm. The mesh can be reordered using the permutation vector in reorder. The reorder algorithms will compute fill-reducing orderings of sparse matrices.
 

METIS can be freely distributed provided that:

• A reference to the following paper is included: “A Fast and Highly Quality Multilevel Scheme for Partitioning Irregular Graphs”. George Karypis and Vipin Kumar. SIAM Journal on Scientific Computing, Vol. 20, No. 1, pp. 359—392, 1999.
• The original documentation (PDF file of the manual) and copyright notice is include
• METIS 4.0 Copyright 2001-06, Regents of the University of Minnesota
  

metis / partition / metis_partmeshnodal | metis_partmeshdual/ node | dual / npartitions / inodeprt / ielemprt

metis / reorder / metis_edgend | metis_nodend / node | dual / [iperm] / [invperm]

metis / reorder / mmetis_nodewnd / node | dual / [iperm] / [invperm] / ivert_weight

metis / partition / metis_partmeshnodal / node / 32 / inodeprt / ielemprt
metis / partition / metis_partmeshdual / dual / 32 / inodeprt / ielemprt
metis / partition / metis_partmeshnodal / node / 32 / -def- / -def-
metis / partition / metis_partmeshnodal / node / 32

metis / reorder / metis_edgend / dual
metis / reorder / metis_nodend / node
metis / reorder / metis_nodend / dual
metis / reorder / metis_nodend / dual / -def- / -def-
metis / reorder / metis_nodend / dual / ieprm1 / ieinvprm1
metis / reorder / metis_edgend / node
reorder/-def-/ieprm1

*
* Build some meshes, tri,quad,hex,tet
*
define / NP / 21
cmo / create / mo_hex / / / hex
createpts / brick / xyz / NP NP NP / 0. 0. 0. / 1. 1. 1. / 1 1 1
cmo / setatt / mo_hex / itetclr / 1 0 0 / 1
resetpts / itp

define / NP / 101
cmo/create/mo_qua/ / / quad
quadxy/ NP NP / 0. 0. 0. / 1. 0. 0. / 1. 1. 0. / 0. 1. 0.
createpts/brick/xyz/NP NP 1/1 0 0 / connect
cmo / setatt / mo_qua / itetclr / 1 0 0 / 1
resetpts / itp

hextotet / 4 / mo_tri / mo_qua
resetpts / itp

hextotet / 24 / mo_tet / mo_hex
resetpts / itp

cmo / status / brief
*
* Run Metis partition into 16, 33 and 128
*
cmo / select / mo_qua
metis/partition/metis_partmeshnodal/node/ 16 idn016 ide016                         
metis/partition/metis_partmeshnodal/node/ 33 idn033 ide033                         
metis/partition/metis_partmeshnodal/node/128 idn128 ide128    
metis/partition/metis_partmeshdual/dual/ 16  iddn016 idde016
metis/partition/metis_partmeshdual/dual/ 33  iddn033 idde033
metis/partition/metis_partmeshdual/dual/128  iddn128 idde128
metis / reorder / metis_nodend / node / iperm1 / invperm1

cmo / select / mo_tri
metis/partition/metis_partmeshnodal/node/ 16 idn016 ide016                         
metis/partition/metis_partmeshnodal/node/ 33 idn033 ide033                         
metis/partition/metis_partmeshnodal/node/ 128 idn128 ide128    
metis/partition/metis_partmeshdual/dual/ 16  iddn016 idde016
metis/partition/metis_partmeshdual/dual/ 33  iddn033 idde033
metis/partition/metis_partmeshdual/dual/128  iddn128 idde128
metis / reorder / metis_nodend / node / iperm1 / invperm1

cmo / select / mo_hex
metis/partition/metis_partmeshnodal/node/ 16 idn016 ide016                         
metis/partition/metis_partmeshnodal/node/ 33 idn033 ide033                         
metis/partition/metis_partmeshnodal/node/ 128 idn128 ide128    
metis/partition/metis_partmeshdual/dual/ 16  iddn016 idde016
metis/partition/metis_partmeshdual/dual/ 33  iddn033 idde033
metis/partition/metis_partmeshdual/dual/128  iddn128 idde128
metis / reorder / metis_nodend / node / iperm1 / invperm1

cmo / select / mo_tet
metis/partition/metis_partmeshnodal/node/ 16 idn016 ide016                         
metis/partition/metis_partmeshnodal/node/ 33 idn033 ide033                         
metis/partition/metis_partmeshnodal/node/ 128 idn128 ide128    
metis/partition/metis_partmeshdual/dual/ 16  iddn016 idde016
metis/partition/metis_partmeshdual/dual/ 33  iddn033 idde033
metis/partition/metis_partmeshdual/dual/128  iddn128 idde128
metis / reorder / metis_nodend / node / iperm1 / invperm1

dump /  gmv / metis_qua.gmv / mo_qua
dump /  gmv / metis_tri.gmv / mo_tri
dump /  gmv / metis_hex.gmv / mo_hex
dump /  gmv / metis_tet.gmv / mo_tet
*
* Create an attribute which is the node number
*
cmo / set_id / mo_qua / node / idnode0
cmo / set_id / mo_tri / node / idnode0
cmo / set_id / mo_hex / node / idnode0
cmo / set_id / mo_tet / node / idnode0
*
* Reorder each mesh using the Metis permutation vector
*
reorder / mo_qua / iperm1
reorder / mo_tri / iperm1
reorder / mo_hex / iperm1
reorder / mo_tet / iperm1
*
* Create an attribute which is the node number after reorder
*
cmo / set_id / mo_qua / node / idnode1
cmo / set_id / mo_tri / node / idnode1
cmo / set_id / mo_hex / node / idnode1
cmo / set_id / mo_tet / node / idnode1

dump /  gmv / metis_qua_reorder.gmv / mo_qua
dump /  gmv / metis_tri_reorder.gmv / mo_tri
dump /  gmv / metis_hex_reorder.gmv / mo_hex
dump /  gmv / metis_tet_reorder.gmv / mo_tet

finish