读取第一列作为非矩形矩阵的矩阵标题

Question

我试图在邻接矩阵中读取以图形方式创建网络 我可以用这个读取数据：

Matrix_One <- read.csv("Network Matrix.csv", header=TRUE)
Matrix <- as.matrix(Matrix_One)
first_network <- graph.adjacency(Matrix, mode= "directed", weighted=NULL)

但是这并没有承认第一列是标题，因为我收到了这条警告信息：

  

graph.adjacency.dense出错（adjmatrix，mode = mode，weighted = weighted，：     在structure_generators.c：273：非方矩阵，非方矩阵

知道如何让R读取column1作为标题吗？

Answer 1

您想要删除Matrix的第一列，如下所示：

Matrix <- as.matrix(Matrix_One)[,-1]

如果您的邻接矩阵的值是数字，建议您使用data.matrix()而不是as.matrix()来获取数值而不是矩阵中的字符串。通常，邻接矩阵中的值是与作为数值给出的每个边权重相对应的权重。

要让R将您的数据作为可用的邻接矩阵读取，请考虑以下因素：

 # Assuming your csv file is like this...
csv <- "X,A,B,C,B,E
        A,0,0,1,0,1
        B,1,0,0,0,0
        C,1,1,0,0,0
        D,1,0,0,0,0
        E,0,0,0,0,0"
# ... with first row and column indicating node name in your network.

# To keep names, we could keep the header and use it as a list of nodes:
Matrix_One <- read.csv2("Network Matrix.csv", sep=",", header=TRUE)
Nodelist <- names(Matrix_One)[-1]

# The matrix should include the first row (which is data),
# but not the first column (which too contains node-names) of the df:
Matrix <- data.matrix(Matrix_One)[,-1]
# As the matrix is now of the size N by N, row- and colnames makes for a neat matrix:
rownames(Matrix) <- colnames(Matrix) <- Nodelist

# Look at it
Matrix

# Use igraph to make a graph-object and visualize it
library(igraph)
g <- graph_from_adjacency_matrix(Matrix, mode="directed", weighted=NULL)
plot(g)

包graph已过时（我相信已从CRAN中移除）。上面的示例使用igrpah代替，这是一个综合的网络数据管理包，具有一些很好的可视化。上面代码的结果将是这样的：

如果您选择坚持graph，那么您的first_network <- graph.adjacency(Matrix, mode= "directed", weighted=NULL)也会占据广场Matrix。