1function gbtest61
2%GBTEST61 test GrB.laplacian
3
4% SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2017-2021, All Rights Reserved.
5% SPDX-License-Identifier: GPL-3.0-or-later
6
7rng ('default') ;
8n = 10 ;
9A = sprand (n, n, 0.4) ;
10
11S = tril (A, -1) ;
12S = S+S' ;
13G = GrB (S) ;
14
15L0 = laplacian (graph (S, 'OmitSelfLoops')) ;
16
17% GrB.laplacian places explicit zeros on the diagonal
18L1 = GrB.laplacian (S) ;
19L2 = GrB.laplacian (G) ;
20L3 = GrB.laplacian (G, 'double', 'check') ;
21
22assert (norm (L0-L1,1) == 0) ;
23assert (isequal (GrB.offdiag (L0), GrB.offdiag (L1))) ;
24assert (isequal (L0, double (L1))) ;
25
26assert (isequal (L1, L2)) ;
27assert (isequal (L1, L3)) ;
28
29G = GrB (G, 'by row') ;
30
31L2 = GrB.laplacian (G) ;
32L3 = GrB.laplacian (G, 'double', 'check') ;
33
34assert (norm (L0-L2,1) == 0) ;
35assert (isequal (GrB.offdiag (L0), GrB.offdiag (L2))) ;
36assert (isequal (L2, L3)) ;
37
38types = { 'double', 'single', 'int8', 'int16', 'int32', 'int64' } ;
39for k = 1:6
40    type = types {k} ;
41    L2 = GrB.laplacian (G, type) ;
42    assert (isequal (GrB.type (L2), type)) ;
43    assert (isequal (L0, double (L2))) ;
44end
45
46
47fprintf ('gbtest61: all tests passed\n') ;
48
49