$$LSI = \frac{E} {\min E}$$
where \(E\) is the total edge length in cell surfaces and \(\min E\)
is the minimum total edge length in cell surfaces.
LSI is an 'Aggregation metric'. It is the ratio between the actual landscape edge length
and the hypothetical minimum edge length. The minimum edge length equals
the edge length if only one patch would be present.
Behaviour
Equals LSI = 1 when only one squared patch is present.
Increases, without limit, as the length of the actual edges increases, i.e.
the patches become less compact.