1. edgelist ⇔ graph
graph_from_edgelist()
graph_from_data_frame()
as_data_frame(g)
as_edgelist(g)
get.edgelist(g)
注意， graph_from_data_frame 和as_data_frame 是可以将边的权重纳入进去的
2. adjacency matrix ⇔ graph
as_adjacency_matrix(g)
graph_from_adjacency_matrix()
3. edgelist ⇔ adjacency matrix
不通过graph转换也是可以的，使用pivot_wider 或者 pivot_longer
## EXAMPLE
library(tidyr)
fish_encounters %>%
pivot_wider(names_from = station, values_from = seen, values_fill = 0) %>% tibble::column_to_rownames("fish")
或者使用reshape2::melt函数也可以实现
