问题
I'm having a data.frame and now I want to convert each row to a list with as keys the column names and values the frame values of that respective row.
f <- function(row) { mongo.bson.from.list(row to list) }
apply(df, 1, f)
the data frame looks like this
> h
id stamp stmt1 stmt2 stmt3 stmt4 stmt5 stmt6 stmt7 stmt8
1 1 1398288482 "0" "1" "0" "1" "1" "1" "0" "1"
2 2 1398288765 "1" "0" "0" "0" "1" "1" "0" "0"
3 3 1398288804 "1" "1" "1" "1" "1" "1" "1" "1"
what I want is an automated way to transform each row of the dataframe into
list(id=1, stamp=1398288482, stmt1="0", stmt2="1", ...)
回答1:
It's interesting to look at variations on @akrun's suggestion:
lapply(split(h, 1:nrow(h)), as.list) # does deliver the requested object
lapply(split(h, 1:nrow(h)), list) # a three element list with named atomic vectors
lapply(split(h, 1:nrow(h)), c) # same as first
lapply(split(h, 1:nrow(h)), structure) #looks the same as first, but are actually data.frames
If you wanted a "normalized" form, the reshape( ..., direction="long")-approach might be useful:
> reshape(h, varying=3:10, direction="long", sep="")
id stamp time stmt
1.1 1 1398288482 1 0
2.1 2 1398288765 1 1
3.1 3 1398288804 1 1
1.2 1 1398288482 2 1
2.2 2 1398288765 2 0
3.2 3 1398288804 2 1
1.3 1 1398288482 3 0
2.3 2 1398288765 3 0
3.3 3 1398288804 3 1
1.4 1 1398288482 4 1
2.4 2 1398288765 4 0
3.4 3 1398288804 4 1
1.5 1 1398288482 5 1
2.5 2 1398288765 5 1
3.5 3 1398288804 5 1
1.6 1 1398288482 6 1
2.6 2 1398288765 6 1
3.6 3 1398288804 6 1
1.7 1 1398288482 7 0
2.7 2 1398288765 7 0
3.7 3 1398288804 7 1
1.8 1 1398288482 8 1
2.8 2 1398288765 8 0
3.8 3 1398288804 8 1
来源：https://stackoverflow.com/questions/26563975/r-data-frame-rows-to-list