Scilab Function
Last update : 5/9/2006

eff - Calculate the efficiency of the network

### Calling Sequence

  `e = eff(t)`

### Parameters

- `t` : the matrix converted by tran function
- `e` : a real number

### Description

  Calculate the efficiency of the network. The function choose the harmonic mean of geodesic lengths to represent the so-called efficiency of graph.

### See Also

`attack` ,

### Authors

  Wubo