MESHDECOMP
The MESHDECOMP is an open source project for decomposition of meshes, which will be used in parallel computing. The MESHDECOMP code is a part of SIFEL open source project and is located in PREP/PARTITIONING/. The code uses keywords from SIFEL. The MESHDECOMP code has four modes. The first mode - preprocessing - creates dual graph from finite element mesh. This dual graph is then used in graph partitioners - METIS, CHACO, PARTY and JOSTLE. The second mode - postprocessing - creates decomposed mesh (several files with mesh topology) form output of mentioned partitioners. The third mode - all - is complex and directly use METIS library for partitioning. In such a case, sequential mesh is input and decomposed mesh is output. The last mode - aggregates - is for sequential computation with aggregates - BOSS preconditioning.

The syntax for usage is:
./meshdecomp file.dec,
where file.dec is a file with informations about mesh and decomposition. File is split into two parts - sec_files and sec_part.

The structure of the part sec_files is following
begsec_files # section with informations about sequential meshes and mesh description
topology_file file.top # file with sequential mesh
mesh_format sifel # format of sequential mesh - sifel or t3d
edge_numbering 1 # edge numbering
endsec_files
The sec_part has different structure for each option of processing. The first line includes the type of processing. Syntax of sec_part section:
begsec_part # section with partitioning data
processing preprocessing | postprocessing | all | aggregates

endsec_part
All types of processing can be used in case of METIS. In all other cases, preprocessing or postprocessing can be only used.

Preprocessing creates dual graph for graph partitioners. There is structure sec_part
partType METIS | JOSTLE | CHACO | PARTY
weigh_graph noweight | nodalweight | edgeweight | nodealedgeweight | multiconstrain

weight_option default | user file_with_weights weightf, where weightf is file with weights
graph_output_file graphf, where graphf is file for output dual graph
Several examples of file.dec in case of preprocessing:
Mesh is in sifel format and dual unweighted graph will be created for JOSTLE. The file.top includes the following data:
121
1 0.000000e+00 0.000000e+00 0.0 5 1 1 2 1 2 4 3 1 4 1
2 0.000000e+00 1.000000e-01 0.0 3 2 4 3 1 4 1
3 0.000000e+00 2.000000e-01 0.0 3 2 4 3 1 4 1
4 0.000000e+00 3.000000e-01 0.0 3 2 4 3 1 4 1
5 0.000000e+00 4.000000e-01 0.0 3 2 4 3 1 4 1
6 0.000000e+00 5.000000e-01 0.0 3 2 4 3 1 4 1
7 0.000000e+00 6.000000e-01 0.0 3 2 4 3 1 4 1
8 0.000000e+00 7.000000e-01 0.0 3 2 4 3 1 4 1
9 0.000000e+00 8.000000e-01 0.0 3 2 4 3 1 4 1
10 0.000000e+00 9.000000e-01 0.0 3 2 4 3 1 4 1
11 0.000000e+00 1.000000e+00 0.0 5 1 4 2 3 2 4 3 1 4 1
12 1.000000e-01 0.000000e+00 0.0 3 2 1 3 1 4 1
13 1.000000e-01 1.000000e-01 0.0 2 3 1 4 1
14 1.000000e-01 2.000000e-01 0.0 2 3 1 4 1
15 1.000000e-01 3.000000e-01 0.0 2 3 1 4 1
16 1.000000e-01 4.000000e-01 0.0 2 3 1 4 1
17 1.000000e-01 5.000000e-01 0.0 2 3 1 4 1
18 1.000000e-01 6.000000e-01 0.0 2 3 1 4 1
19 1.000000e-01 7.000000e-01 0.0 2 3 1 4 1
20 1.000000e-01 8.000000e-01 0.0 2 3 1 4 1
21 1.000000e-01 9.000000e-01 0.0 2 3 1 4 1
22 1.000000e-01 1.000000e+00 0.0 3 2 3 3 1 4 1
23 2.000000e-01 0.000000e+00 0.0 3 2 1 3 1 4 1
24 2.000000e-01 1.000000e-01 0.0 2 3 1 4 1
25 2.000000e-01 2.000000e-01 0.0 2 3 1 4 1
26 2.000000e-01 3.000000e-01 0.0 2 3 1 4 1
27 2.000000e-01 4.000000e-01 0.0 2 3 1 4 1
28 2.000000e-01 5.000000e-01 0.0 2 3 1 4 1
29 2.000000e-01 6.000000e-01 0.0 2 3 1 4 1
30 2.000000e-01 7.000000e-01 0.0 2 3 1 4 1
31 2.000000e-01 8.000000e-01 0.0 2 3 1 4 1
32 2.000000e-01 9.000000e-01 0.0 2 3 1 4 1
33 2.000000e-01 1.000000e+00 0.0 3 2 3 3 1 4 1
34 3.000000e-01 0.000000e+00 0.0 3 2 1 3 1 4 1
35 3.000000e-01 1.000000e-01 0.0 2 3 1 4 1
36 3.000000e-01 2.000000e-01 0.0 2 3 1 4 1
37 3.000000e-01 3.000000e-01 0.0 2 3 1 4 1
38 3.000000e-01 4.000000e-01 0.0 2 3 1 4 1
39 3.000000e-01 5.000000e-01 0.0 2 3 1 4 1
40 3.000000e-01 6.000000e-01 0.0 2 3 1 4 1
41 3.000000e-01 7.000000e-01 0.0 2 3 1 4 1
42 3.000000e-01 8.000000e-01 0.0 2 3 1 4 1
43 3.000000e-01 9.000000e-01 0.0 2 3 1 4 1
44 3.000000e-01 1.000000e+00 0.0 3 2 3 3 1 4 1
45 4.000000e-01 0.000000e+00 0.0 3 2 1 3 1 4 1
46 4.000000e-01 1.000000e-01 0.0 2 3 1 4 1
47 4.000000e-01 2.000000e-01 0.0 2 3 1 4 1
48 4.000000e-01 3.000000e-01 0.0 2 3 1 4 1
49 4.000000e-01 4.000000e-01 0.0 2 3 1 4 1
50 4.000000e-01 5.000000e-01 0.0 2 3 1 4 1
51 4.000000e-01 6.000000e-01 0.0 2 3 1 4 1
52 4.000000e-01 7.000000e-01 0.0 2 3 1 4 1
53 4.000000e-01 8.000000e-01 0.0 2 3 1 4 1
54 4.000000e-01 9.000000e-01 0.0 2 3 1 4 1
55 4.000000e-01 1.000000e+00 0.0 3 2 3 3 1 4 1
56 5.000000e-01 0.000000e+00 0.0 3 2 1 3 1 4 1
57 5.000000e-01 1.000000e-01 0.0 2 3 1 4 1
58 5.000000e-01 2.000000e-01 0.0 2 3 1 4 1
59 5.000000e-01 3.000000e-01 0.0 2 3 1 4 1
60 5.000000e-01 4.000000e-01 0.0 2 3 1 4 1
61 5.000000e-01 5.000000e-01 0.0 2 3 1 4 1
62 5.000000e-01 6.000000e-01 0.0 2 3 1 4 1
63 5.000000e-01 7.000000e-01 0.0 2 3 1 4 1
64 5.000000e-01 8.000000e-01 0.0 2 3 1 4 1
65 5.000000e-01 9.000000e-01 0.0 2 3 1 4 1
66 5.000000e-01 1.000000e+00 0.0 3 2 3 3 1 4 1
67 6.000000e-01 0.000000e+00 0.0 3 2 1 3 1 4 1
68 6.000000e-01 1.000000e-01 0.0 2 3 1 4 1
69 6.000000e-01 2.000000e-01 0.0 2 3 1 4 1
70 6.000000e-01 3.000000e-01 0.0 2 3 1 4 1
71 6.000000e-01 4.000000e-01 0.0 2 3 1 4 1
72 6.000000e-01 5.000000e-01 0.0 2 3 1 4 1
73 6.000000e-01 6.000000e-01 0.0 2 3 1 4 1
74 6.000000e-01 7.000000e-01 0.0 2 3 1 4 1
75 6.000000e-01 8.000000e-01 0.0 2 3 1 4 1
76 6.000000e-01 9.000000e-01 0.0 2 3 1 4 1
77 6.000000e-01 1.000000e+00 0.0 3 2 3 3 1 4 1
78 7.000000e-01 0.000000e+00 0.0 3 2 1 3 1 4 1
79 7.000000e-01 1.000000e-01 0.0 2 3 1 4 1
80 7.000000e-01 2.000000e-01 0.0 2 3 1 4 1
81 7.000000e-01 3.000000e-01 0.0 2 3 1 4 1
82 7.000000e-01 4.000000e-01 0.0 2 3 1 4 1
83 7.000000e-01 5.000000e-01 0.0 2 3 1 4 1
84 7.000000e-01 6.000000e-01 0.0 2 3 1 4 1
85 7.000000e-01 7.000000e-01 0.0 2 3 1 4 1
86 7.000000e-01 8.000000e-01 0.0 2 3 1 4 1
87 7.000000e-01 9.000000e-01 0.0 2 3 1 4 1
88 7.000000e-01 1.000000e+00 0.0 3 2 3 3 1 4 1
89 8.000000e-01 0.000000e+00 0.0 3 2 1 3 1 4 1
90 8.000000e-01 1.000000e-01 0.0 2 3 1 4 1
91 8.000000e-01 2.000000e-01 0.0 2 3 1 4 1
92 8.000000e-01 3.000000e-01 0.0 2 3 1 4 1
93 8.000000e-01 4.000000e-01 0.0 2 3 1 4 1
94 8.000000e-01 5.000000e-01 0.0 2 3 1 4 1
95 8.000000e-01 6.000000e-01 0.0 2 3 1 4 1
96 8.000000e-01 7.000000e-01 0.0 2 3 1 4 1
97 8.000000e-01 8.000000e-01 0.0 2 3 1 4 1
98 8.000000e-01 9.000000e-01 0.0 2 3 1 4 1
99 8.000000e-01 1.000000e+00 0.0 3 2 3 3 1 4 1
100 9.000000e-01 0.000000e+00 0.0 3 2 1 3 1 4 1
101 9.000000e-01 1.000000e-01 0.0 2 3 1 4 1
102 9.000000e-01 2.000000e-01 0.0 2 3 1 4 1
103 9.000000e-01 3.000000e-01 0.0 2 3 1 4 1
104 9.000000e-01 4.000000e-01 0.0 2 3 1 4 1
105 9.000000e-01 5.000000e-01 0.0 2 3 1 4 1
106 9.000000e-01 6.000000e-01 0.0 2 3 1 4 1
107 9.000000e-01 7.000000e-01 0.0 2 3 1 4 1
108 9.000000e-01 8.000000e-01 0.0 2 3 1 4 1
109 9.000000e-01 9.000000e-01 0.0 2 3 1 4 1
110 9.000000e-01 1.000000e+00 0.0 3 2 3 3 1 4 1
111 1.000000e+00 0.000000e+00 0.0 5 1 2 2 1 2 2 3 1 4 1
112 1.000000e+00 1.000000e-01 0.0 3 2 2 3 1 4 1
113 1.000000e+00 2.000000e-01 0.0 3 2 2 3 1 4 1
114 1.000000e+00 3.000000e-01 0.0 3 2 2 3 1 4 1
115 1.000000e+00 4.000000e-01 0.0 3 2 2 3 1 4 1
116 1.000000e+00 5.000000e-01 0.0 3 2 2 3 1 4 1
117 1.000000e+00 6.000000e-01 0.0 3 2 2 3 1 4 1
118 1.000000e+00 7.000000e-01 0.0 3 2 2 3 1 4 1
119 1.000000e+00 8.000000e-01 0.0 3 2 2 3 1 4 1
120 1.000000e+00 9.000000e-01 0.0 3 2 2 3 1 4 1
121 1.000000e+00 1.000000e+00 0.0 5 1 3 2 2 2 3 3 1 4 1

100
1 5 1 12 13 2 1 1 0 0 4 1
2 5 2 13 14 3 1 0 0 0 4 1
3 5 3 14 15 4 1 0 0 0 4 1
4 5 4 15 16 5 1 0 0 0 4 1
5 5 5 16 17 6 1 0 0 0 4 1
6 5 6 17 18 7 1 0 0 0 4 1
7 5 7 18 19 8 1 0 0 0 4 1
8 5 8 19 20 9 1 0 0 0 4 1
9 5 9 20 21 10 1 0 0 0 4 1
10 5 10 21 22 11 1 0 0 3 4 1
11 5 12 23 24 13 1 1 0 0 0 1
12 5 13 24 25 14 1 0 0 0 0 1
13 5 14 25 26 15 1 0 0 0 0 1
14 5 15 26 27 16 1 0 0 0 0 1
15 5 16 27 28 17 1 0 0 0 0 1
16 5 17 28 29 18 1 0 0 0 0 1
17 5 18 29 30 19 1 0 0 0 0 1
18 5 19 30 31 20 1 0 0 0 0 1
19 5 20 31 32 21 1 0 0 0 0 1
20 5 21 32 33 22 1 0 0 3 0 1
21 5 23 34 35 24 1 1 0 0 0 1
22 5 24 35 36 25 1 0 0 0 0 1
23 5 25 36 37 26 1 0 0 0 0 1
24 5 26 37 38 27 1 0 0 0 0 1
25 5 27 38 39 28 1 0 0 0 0 1
26 5 28 39 40 29 1 0 0 0 0 1
27 5 29 40 41 30 1 0 0 0 0 1
28 5 30 41 42 31 1 0 0 0 0 1
29 5 31 42 43 32 1 0 0 0 0 1
30 5 32 43 44 33 1 0 0 3 0 1
31 5 34 45 46 35 1 1 0 0 0 1
32 5 35 46 47 36 1 0 0 0 0 1
33 5 36 47 48 37 1 0 0 0 0 1
34 5 37 48 49 38 1 0 0 0 0 1
35 5 38 49 50 39 1 0 0 0 0 1
36 5 39 50 51 40 1 0 0 0 0 1
37 5 40 51 52 41 1 0 0 0 0 1
38 5 41 52 53 42 1 0 0 0 0 1
39 5 42 53 54 43 1 0 0 0 0 1
40 5 43 54 55 44 1 0 0 3 0 1
41 5 45 56 57 46 1 1 0 0 0 1
42 5 46 57 58 47 1 0 0 0 0 1
43 5 47 58 59 48 1 0 0 0 0 1
44 5 48 59 60 49 1 0 0 0 0 1
45 5 49 60 61 50 1 0 0 0 0 1
46 5 50 61 62 51 1 0 0 0 0 1
47 5 51 62 63 52 1 0 0 0 0 1
48 5 52 63 64 53 1 0 0 0 0 1
49 5 53 64 65 54 1 0 0 0 0 1
50 5 54 65 66 55 1 0 0 3 0 1
51 5 56 67 68 57 1 1 0 0 0 1
52 5 57 68 69 58 1 0 0 0 0 1
53 5 58 69 70 59 1 0 0 0 0 1
54 5 59 70 71 60 1 0 0 0 0 1
55 5 60 71 72 61 1 0 0 0 0 1
56 5 61 72 73 62 1 0 0 0 0 1
57 5 62 73 74 63 1 0 0 0 0 1
58 5 63 74 75 64 1 0 0 0 0 1
59 5 64 75 76 65 1 0 0 0 0 1
60 5 65 76 77 66 1 0 0 3 0 1
61 5 67 78 79 68 1 1 0 0 0 1
62 5 68 79 80 69 1 0 0 0 0 1
63 5 69 80 81 70 1 0 0 0 0 1
64 5 70 81 82 71 1 0 0 0 0 1
65 5 71 82 83 72 1 0 0 0 0 1
66 5 72 83 84 73 1 0 0 0 0 1
67 5 73 84 85 74 1 0 0 0 0 1
68 5 74 85 86 75 1 0 0 0 0 1
69 5 75 86 87 76 1 0 0 0 0 1
70 5 76 87 88 77 1 0 0 3 0 1
71 5 78 89 90 79 1 1 0 0 0 1
72 5 79 90 91 80 1 0 0 0 0 1
73 5 80 91 92 81 1 0 0 0 0 1
74 5 81 92 93 82 1 0 0 0 0 1
75 5 82 93 94 83 1 0 0 0 0 1
76 5 83 94 95 84 1 0 0 0 0 1
77 5 84 95 96 85 1 0 0 0 0 1
78 5 85 96 97 86 1 0 0 0 0 1
79 5 86 97 98 87 1 0 0 0 0 1
80 5 87 98 99 88 1 0 0 3 0 1
81 5 89 100 101 90 1 1 0 0 0 1
82 5 90 101 102 91 1 0 0 0 0 1
83 5 91 102 103 92 1 0 0 0 0 1
84 5 92 103 104 93 1 0 0 0 0 1
85 5 93 104 105 94 1 0 0 0 0 1
86 5 94 105 106 95 1 0 0 0 0 1
87 5 95 106 107 96 1 0 0 0 0 1
88 5 96 107 108 97 1 0 0 0 0 1
89 5 97 108 109 98 1 0 0 0 0 1
90 5 98 109 110 99 1 0 0 3 0 1
91 5 100 111 112 101 1 1 2 0 0 1
92 5 101 112 113 102 1 0 2 0 0 1
93 5 102 113 114 103 1 0 2 0 0 1
94 5 103 114 115 104 1 0 2 0 0 1
95 5 104 115 116 105 1 0 2 0 0 1
96 5 105 116 117 106 1 0 2 0 0 1
97 5 106 117 118 107 1 0 2 0 0 1
98 5 107 118 119 108 1 0 2 0 0 1
99 5 108 119 120 109 1 0 2 0 0 1
100 5 109 120 121 110 1 0 2 3 0 1
 file.dec includes following data:
begsec_files
mesh description
topology_file file.top
mesh_format sifel
edge_numbering 1
endsec_files
begsec_part
processing preprocessing
partType JOSTLE
weight_graph noweight
graph_output_file file-graph
endsec_part
The result is file file-graph.grf which contains: 100 342
2 11 12
1 3 11 12 13
2 4 12 13 14
3 5 13 14 15
4 6 14 15 16
5 7 15 16 17
6 8 16 17 18
7 9 17 18 19
8 10 18 19 20
9 19 20
1 2 12 21 22
1 2 3 11 13 21 22 23
2 3 4 12 14 22 23 24
3 4 5 13 15 23 24 25
4 5 6 14 16 24 25 26
5 6 7 15 17 25 26 27
6 7 8 16 18 26 27 28
7 8 9 17 19 27 28 29
8 9 10 18 20 28 29 30
9 10 19 29 30
11 12 22 31 32
11 12 13 21 23 31 32 33
12 13 14 22 24 32 33 34
13 14 15 23 25 33 34 35
14 15 16 24 26 34 35 36
15 16 17 25 27 35 36 37
16 17 18 26 28 36 37 38
17 18 19 27 29 37 38 39
18 19 20 28 30 38 39 40
19 20 29 39 40
21 22 32 41 42
21 22 23 31 33 41 42 43
22 23 24 32 34 42 43 44
23 24 25 33 35 43 44 45
24 25 26 34 36 44 45 46
25 26 27 35 37 45 46 47
26 27 28 36 38 46 47 48
27 28 29 37 39 47 48 49
28 29 30 38 40 48 49 50
29 30 39 49 50
31 32 42 51 52
31 32 33 41 43 51 52 53
32 33 34 42 44 52 53 54
33 34 35 43 45 53 54 55
34 35 36 44 46 54 55 56
35 36 37 45 47 55 56 57
36 37 38 46 48 56 57 58
37 38 39 47 49 57 58 59
38 39 40 48 50 58 59 60
39 40 49 59 60
41 42 52 61 62
41 42 43 51 53 61 62 63
42 43 44 52 54 62 63 64
43 44 45 53 55 63 64 65
44 45 46 54 56 64 65 66
45 46 47 55 57 65 66 67
46 47 48 56 58 66 67 68
47 48 49 57 59 67 68 69
48 49 50 58 60 68 69 70
49 50 59 69 70
51 52 62 71 72
51 52 53 61 63 71 72 73
52 53 54 62 64 72 73 74
53 54 55 63 65 73 74 75
54 55 56 64 66 74 75 76
55 56 57 65 67 75 76 77
56 57 58 66 68 76 77 78
57 58 59 67 69 77 78 79
58 59 60 68 70 78 79 80
59 60 69 79 80
61 62 72 81 82
61 62 63 71 73 81 82 83
62 63 64 72 74 82 83 84
63 64 65 73 75 83 84 85
64 65 66 74 76 84 85 86
65 66 67 75 77 85 86 87
66 67 68 76 78 86 87 88
67 68 69 77 79 87 88 89
68 69 70 78 80 88 89 90
69 70 79 89 90
71 72 82 91 92
71 72 73 81 83 91 92 93
72 73 74 82 84 92 93 94
73 74 75 83 85 93 94 95
74 75 76 84 86 94 95 96
75 76 77 85 87 95 96 97
76 77 78 86 88 96 97 98
77 78 79 87 89 97 98 99
78 79 80 88 90 98 99 100
79 80 89 99 100
81 82 92
81 82 83 91 93
82 83 84 92 94
83 84 85 93 95
84 85 86 94 96
85 86 87 95 97
86 87 88 96 98
87 88 89 97 99
88 89 90 98 100
89 90 99

 Mesh is in sifel format and dual graph with nodal weights will be created for JOSTLE. Weights are computed.
begsec_files
mesh description
topology_file file.top
mesh_format sifel
edge_numbering 1
endsec_files
begsec_part
processing preprocessing
partType JOSTLE
weight_graph nodalweight
weight_option default
graph_output_file file-graph
endsec_part
Mesh is in sifel format and dual graph with nodal weights will be created for JOSTLE. Weights are defined by user.
begsec_files
mesh description
topology_file file.top
mesh_format sifel
edge_numbering 1
endsec_files
begsec_part
processing preprocessing
partType JOSTLE
weight_graph nodalweight
weight_option user
graph_output_file file-graph
endsec_part

Postprocessing creates files with meshes for parallel computing. Creation of such meshes is based on output from graph partitioners and on original sequential mesh. There is structure sec_part.
mesh_description all_nodes | bound_nodes | neg_bound_nodes - type of mesh description of parallel meshes - bound_nodes or all_nodes (see SIFEL manual)
partType METIS | JOSTLE | CHACO | PARTY
number_of_partitions npart , where npart is number of partitions into which original mesh was decomposed)
partitioning_file partf (where partf is file with decomposition of the sequential mesh.)
output_file_name outputfname (where outputfname is filename for files with decomposed mesh.)
Example of file.dec in case of postprocessing:
Mesh is in sifel format and JOSTLE graph partitioner was used for decomposition. Mesh was decomposed into 4 subdomains.Results are stored in files file-decomp1.top - file-decomp4.top. The file.top is the same as in above examples. The file.grf.ptn contains output from JOSTLE and has the form:
3
3
3
3
3
3
0
0
0
0
3
3
3
3
3
3
0
0
0
0
3
3
3
3
3
0
0
0
0
0
3
3
3
3
3
0
0
0
0
0
3
3
3
1
1
0
0
0
0
0
1
1
1
1
1
1
2
2
0
0
1
1
1
1
1
2
2
2
2
2
1
1
1
1
2
2
2
2
2
2
1
1
1
1
2
2
2
2
2
2
1
1
1
1
2
2
2
2
2
2
begsec_files
mesh description
topology_file file.top
mesh_format sifel
mesh_description bound_nodes
edge_numbering 1
endsec_files
begsec_part
processing postprocessing
mesh_description bound_nodes
partType JOSTLE
number_of_partitions 4
partitioning_file file-graph.grf.ptn
output_file_name file-decomp.top

All in processing can be use only with METIS partitioning and creates parallel topology directly from sequential mesh with the help of METIS library. There is structure sec_part with this option:
number_of_partitions npart , where npart is number of partitions into which original mesh was decomposed)
weight_graph noweight | nodalweight | edgeweight | nodealedgeweight | multiconstrain
weight_option default | user
file_with_weights weightf
output_file_name outputfname
partitioning_technique recursive | kway The difference between kway and recursive bisection is described in METIS manual. If the number of partition is smaller than eight recursive bisection is better than kway. Example of file.dec in case of all:
Mesh is in sifel format and METIS graph partitioner will be used for decomposition. The file.top is the same as in the above examples. Mesh will be decomposed into 4 subdomains. Results are stored in files file-dec1.top, file-dec2.top, file-dec3.top, and file-dec4.top. File.dec contains:
begsec_files
mesh description
topology_file file.top
mesh_format sifel
mesh_description bound_nodes
edge_numbering 1
endsec_files
begsec_part
processing all
mesh_description bound_nodes
number_of_partitions 4
weight_graph noweight
output_file_name file-dec.top
partitioning_technique recursive
endsec_part

Aggregates in processing can be use only with METIS partitioning and reprint sequential topology and uses mesh description for aggregates computation. The structure of section is similar as in all processing. Example of sec_part:
begsec_part
processing aggregates
number_of_aggregates naggreg, where naggreg is number of aggregates
output_file_name newfile.top
partitioning_technique recursive
endsec_part
Jaroslav Broz 2010-11-11