将R中具有不同行长的文件读入列表

Question

I would like to read a file into a list of arrays with each line representing a list element. Each line has a different number of elements and different The first value in the line would be the list key and the remaining data would be the members of the array.

eg file example

1 100,50,2,5,78
2 5,4,2,1
3 1
4 7,2,9,0,23,5,6,7,8,2,3,4
5 1,2,3,4,5,6,7,8,9,0
6 1,8

Answer 1

I think this should work well

dd<-scan("example.txt", list("character", "character"))
Map(function(a,b)b, dd[[1]], strsplit(dd[[2]],","))

Here use use scan to read the first column as one vector and the second as another. Then we strsplit the second on commas and use one of the side-effects of Map to pull the names from the first column and use them as labels of the vectors from the second column. If you wanted the vector values to be numeric you could do

Map(function(a,b) as.numeric(b), dd[[1]], strsplit(dd[[2]],","))

# $`1`
# [1] 100  50   2   5  78
# 
# $`2`
# [1] 5 4 2 1
# 
# $`3`
# [1] 1
# 
# $`4`
#  [1]  7  2  9  0 23  5  6  7  8  2  3  4
# 
# $`5`
#  [1] 1 2 3 4 5 6 7 8 9 0
# 
# $`6`
# [1] 1 8