在R中对数据帧制作加权边缘列表

I have a data set with three columns.

我有一个包含三列的数据集。

X = c("x", "y", "z", "x", "y", "w")
Y = c("a", "b", "c" , "b", "a", "c")
set.seed(3)
Z = sample(10,6)
dat = data.frame(X, Y, Z)

The dat looks like

dat的样子

 X Y Z
1 x a 2
2 y b 8
3 z c 4
4 x b 3
5 y a 9
6 w c 6

I want to transform the above data into the format that the rows are X and the columns are Y and the values in the matrix are Z. Essentially I want the following:

我想把上面的数据转换成行为X，列为Y，矩阵值为z的格式。

    a   b    c
x   2   3    0
y   9   8    0
z   0   0    4
w   0   0    6

This is somewhat similar to edge list to adjacency matrix, except the data matrix is not square. Please help. Thanks!

这有点类似于边列表与邻接矩阵，除了数据矩阵不是方阵。请帮助。谢谢!

1 个解决方案

#1

Try

试一试

library(reshape2)
acast(dat, X~Y, value.var='Z', fill=0)

To get the rows in order as the expected result

使行按照预期结果排列

acast(dat, factor(X, levels=unique(X))~Y, value.var='Z', fill=0)

Or as @thelatemail commented

或@thelatemail评论

xtabs(Z~X+Y, data= dat)[unique(dat$X),]

Or a modified version if both columns are not in order

或者，如果两个列都不符合要求，则修改版本。

with(dat, xtabs(Z ~ X + Y)[unique(X), unique(Y)])

#1

Try

试一试

library(reshape2)
acast(dat, X~Y, value.var='Z', fill=0)