问题
I have a dataframe which has 100 rows and 10 columns, i wonder how I can merge all the 100 rows into just one row? Thanks.
mydata=seq(1,1000)
mydata=as.data.frame(matrix(mydata,nrow = 100,ncol = 10,byrow=T))
the result should be like this：(just a single row)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 ……
回答1:
We can get the transpose and concatenate to a vector. Note that the transpose converts to a matrix and there is no need to call as.matrix.
as.vector(t(mydata))
Or we can use unlist after splitting the rows into a list.
unlist(lapply(seq_len(nrow(mydata)), function(i) mydata[i,]))
回答2:
Matrix are indexed by column so I am guessing you may just need to transpose your data and then construct a new matrix from it:
matrix(t(as.matrix(mydata)), nrow = 1)
Or you can convert it to a vector after the transposing depending on what you need:
as.vector(t(as.matrix(mydata)))
来源：https://stackoverflow.com/questions/38387031/how-to-combine-all-rows-into-a-single-row