reading a table in R?

问题

I have a txt file with the following structure:

NAME     DATA1    DATA2
a        10       1,2,3
b        6        8,9
c        20       5,6,7 ,8

The first line represent the header and the data is separated by tabs. I need to put the elements of DATA1 in a list or vector in a way that I can traverse the elements one by one.

Also I need to extract the elements of DATA2 for each NAME and to put them in a list so I can traverse then individually, e.g. get the elements 8,9 for NAME b and put it into a list. (Note that the third record has a space in the list in DATA2 between the 7 and the comma).

How I can do that both operations? I know that I can use read.table and $ for accessing individual elements, but I am stuck.

info<-read.table("table1", header=FALSE,sep="\t")
namelist<-list(info$NAME)

回答1:

Run this demo and look at the structure of n, d1, and d2 -- that should help you get going:

df = read.table(text="NAME\tDATA1\tDATA2
a\t10\t1,2,3
b\t6\t8,9
c\t20\t5,6,7 ,8", 
                header= TRUE, 
                stringsAsFactors=FALSE,
                sep='\t')

n  = df$NAME
d1 = df$DATA1
d2 = lapply(strsplit(df$DATA2, ","), 
            as.numeric)
names(d2) = n

d2['b'][1] # access first element in list named 'b'

lapply(d2, FUN=mean) # mean of all rows in d2

来源：https://stackoverflow.com/questions/11470734/reading-a-table-in-r