r - 如何使用预定义的顶点 ID 创建 igraph？

Question

我有顶点的id's和坐标。(x,y)边缘列表el也是已知的。我需要创建一个空间图。

我的尝试如下：

library(igraph)
                      
id <- c(106, 110, 107, 102, 104, 103, 108, 111, 109, 101)
        
        cx <- c(270.2798, 156.4124, 270.2798, 100.0332, 156.4124, 100.0332, 156.4124, 156.4124, 156.4124, 100.0035)
                
cy <- c(401.2903, 420.2904, 470.4120, 401.2903, 348.2904, 348.2904, 470.4120, 401.2903, 436.8926, 470.1633)
        
el <- c(101,102, 102,103, 103,104, 104,111, 111,106,
                106,107, 107,108, 108,101, 108,109, 110,111)
        
dfw <- data.frame(id, cx, cy)
    
g2 <- make_empty_graph() %>%
add_vertices(nrow(dfw)) %>%
add_edges(el) # error is here
    
V(g2)$names <- dfw$id
    
mylayout2 <- as.matrix(cbind(dfw$cx, -dfw$cy))
    
plot(g2, layout=mylayout2,
               vertex.size = 10,
               vertex.label = V(g2)$name,  
               vertex.label.cex=.95, 
         )

我有错误

Error in add_edges(., el) : 
  At type_indexededgelist.c:272 : cannot add edges, Invalid vertex id

预期结果是：

问题。如何使用预定义id's的顶点添加边？

标签： rigraph

Answer 1

首先，要将 101、102 等转换为dfw我们可以使用的行号match。二、应该是

V(g2)$name <- dfw$id

代替

V(g2)$names <- dfw$id

所以，我们有

g2 <- make_empty_graph() %>% add_vertices(nrow(dfw)) %>% add_edges(match(el, dfw$id))
V(g2)$name <- dfw$id
mylayout2 <- as.matrix(cbind(dfw$cx, -dfw$cy))
plot(g2, layout = mylayout2,
     vertex.size = 10,
     vertex.label = V(g2)$name,  
     vertex.label.cex = .95)