Visualize sparsity pattern
spy(S) plots the sparsity
pattern of any matrix
an integer, plots the sparsity pattern using markers of the specified
a character vector, uses the specified plot marker type and color.
the specified type, color, and size for the plot markers.
S is usually a sparse matrix, but full matrices
are acceptable, in which case the locations of the nonzero elements
which takes much more space to display essentially the same information.
This example plots the 60-by-60 sparse adjacency matrix of the connectivity graph of the Buckminster Fuller geodesic dome. This matrix also represents the soccer ball and the carbon-60 molecule.
B = bucky; spy(B)