如何在 R 中的矢量图上绘制 igraph 对象

如何解决如何在 R 中的矢量图上绘制 igraph 对象

我使用 igraph 和 sf 包。

我有一个 igraph 对象，其顶点具有空间坐标 geo_dist_graph。 顶点名称和坐标如下所示：

grid_grid <- 
structure(list(coords.x1 = c(15.504078,15.704078,15.904078,15.104078,15.304078,15.504078,14.904078,14.304078,13.904078,14.704078,13.704078,14.104078,14.304078),coords.x2 = c(43.835623,43.835623,44.035623,44.235623,44.435623,44.635623,44.835623,45.035623,45.235623,45.435623,45.435623),g9.nodes = c(27,28,29,40,41,42,43,55,56,58,69,81,94,98,108,110,113,114,123,124,128,138,139,141)),class = "data.frame",row.names = c("1","2","3","4","5","6","7","8","9","10","11","12","13","14","15","16","17","18","19","20","21","22","23","24"
))

该图来自一个简单的平方邻接矩阵：

geo_dist_graph <- 
  structure(c(NA,1,NA,NA),.Dim = c(24L,24L))

colnames(geo_dist_graph) <- grid_grid$g9.nodes
row.names(geo_dist_graph) <- grid_grid$g9.nodes

geo_dist_graph <- graph_from_adjacency_matrix(geo_dist_graph,mode = "upper",diag = F)

以这种方式附加的空间坐标：

V(geo_dist_graph)$x <- 
  grid_grid$coords.x1[match(V(geo_dist_graph)$name,grid_grid$g9.nodes)]

V(geo_dist_graph)$y <- 
  grid_grid$coords.x2[match(V(geo_dist_graph)$name,grid_grid$g9.nodes)]

使用 plot 函数时，图形在空间中绘制是正确的。但是当我尝试添加像 plot(map_crop_sp,add = T) 这样的底图时，地图没有显示在图表后面，但没有错误消息。

地图是矢量图，不知道重要不重要。这是用于创建它的代码。

map <- st_read("ne_10m_coastline/ne_10m_coastline.shp")
map_crop <- st_crop(map,xmin = 13.304078,ymin = 43.635623,xmax = 16.503846,ymax = 45.60185)
map_crop_sp <- as(map_crop,Class = "Spatial")

解决方法

回答

由于 igraph 应该在地图的顶部，我将其绘制在第二个位置。我还添加了 rescale = F：

plot(map_crop_sp)
plot(geo_dist_graph,add = T,rescale = F)

基本原理

我输入了 ?plot.igraph。从那里，我找到了 ?igraph.plotting。似乎绘制一个 igraph 对象会重新缩放它 (plot(...,rescale = TRUE):

逻辑常量，是否将坐标重新缩放到[-1,1]x-1,1区间。 tkplot 未实现此参数。

默认为 TRUE，布局将被重新缩放。