igraph的layout布局

做图论的社区检测，需要画图显示，用igraph可以进行可视化。
igraph有几个布局，分别如下：

layout_with_dh ： The Davidson-Harel layout algorithm

Place vertices of a graph on the plane, according to the simulated annealing algorithm by Davidson and Harel.

layout_with_drl：The DrL graph layout generator

DrL is a force-directed graph layout toolbox focused on real-world large-scale graphs, developed by Shawn Martin and colleagues at andia National Laboratories

layout_with_fr：The Fruchterman-Reingold layout algorithm

Place vertices on the plane using the force-directed