MATLAB Mathematics - SERC - Index of

6 Sparse Matrices
The vertices of one pentagon are numbered 1 through 5, the vertices of an
adjacent pentagon are numbered 6 through 10, and so on. The picture on the
following page shows the numbering of half of the nodes (one hemisphere); the
numbering of the other hemisphere is obtained by a reflection about the
equator. Use gplot to produce a graph showing half the nodes. You can add the
node numbers using a for loop.
k = 1:30;
gplot(B(k,k),v);
axis square
for j = 1:30, text(v(j,1),v(j,2), int2str(j)); end
1
14
0.8
0.6
18
17
15
13
11 12
0.4
19
16
2
10
0.2
20
3
9
0
1
6
−0.2
22
4
8
−0.4
23
21
5
7
−0.6
−0.8
24 25
27
26
29
30
−1
28
−1 −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1
To view a template of the nonzero locations in the Bucky ball’s adjacency
matrix, use the spy function:
spy(B)
6-20