读表 Try read.table
with fill=TRUE
:
d1 <- read.table("data.csv", sep = ",", as.is = TRUE, fill = TRUE)
giving:
> d1
V1 V2 V3 V4 V5 V6
1 tasty chicken cinnamon
2 not_tasty butter pepper onion cardamom cayenne
3 tasty olive_oil pepper
4 okay olive_oil onion potato black_pepper
5 not_tasty tomato fenugreek pepper onion potato
6 tasty butter cheese wheat ham
带有 NA 的 read.table
或者用 NA 值填充空单元格添加na.strings = ""
:
d2 <- read.table("data.csv", sep = ",", as.is = TRUE, fill = TRUE, na.strings = "")
giving:
> d2
V1 V2 V3 V4 V5 V6
1 tasty chicken cinnamon <NA> <NA> <NA>
2 not_tasty butter pepper onion cardamom cayenne
3 tasty olive_oil pepper <NA> <NA> <NA>
4 okay olive_oil onion potato black_pepper <NA>
5 not_tasty tomato fenugreek pepper onion potato
6 tasty butter cheese wheat ham <NA>
长表
如果您想要长格式:
library(reshape2)
long <- na.omit(melt(d2, id.var = c("id", "V1"))[-3])
long <- long[order(long$id), ]
giving:
> long
id V1 value
1 1 tasty chicken
7 1 tasty cinnamon
2 2 not_tasty butter
8 2 not_tasty pepper
14 2 not_tasty onion
20 2 not_tasty cardamom
26 2 not_tasty cayenne
3 3 tasty olive_oil
9 3 tasty pepper
4 4 okay olive_oil
10 4 okay onion
16 4 okay potato
22 4 okay black_pepper
5 5 not_tasty tomato
11 5 not_tasty fenugreek
17 5 not_tasty pepper
23 5 not_tasty onion
29 5 not_tasty potato
6 6 tasty butter
12 6 tasty cheese
18 6 tasty wheat
24 6 tasty ham
宽格式 0/1 二进制变量
要将变量部分表示为 0/1 二进制变量,请尝试以下操作:
wide <- cast(id + V1 ~ value, data = long)
wide[-(1:2)] <- 0 + !is.na(wide[-(1:2)])
给出这个:
数据框中的列表
不同的表示形式是数据框中的以下列表,以便ag$value
是字符向量列表:
ag <- aggregate(value ~., transform(long, value = as.character(value)), c)
ag <- ag[order(ag$id), ]
giving:
> ag
id V1 value
4 1 tasty chicken, cinnamon
1 2 not_tasty butter, pepper, onion, cardamom, cayenne
5 3 tasty olive_oil, pepper
3 4 okay olive_oil, onion, potato, black_pepper
2 5 not_tasty tomato, fenugreek, pepper, onion, potato
6 6 tasty butter, cheese, wheat, ham
> str(ag)
'data.frame': 6 obs. of 3 variables:
$ id : int 1 2 3 4 5 6
$ V1 : chr "tasty" "not_tasty" "tasty" "okay" ...
$ value:List of 6
..$ 15: chr "chicken" "cinnamon"
..$ 1 : chr "butter" "pepper" "onion" "cardamom" ...
..$ 17: chr "olive_oil" "pepper"
..$ 11: chr "olive_oil" "onion" "potato" "black_pepper"
..$ 6 : chr "tomato" "fenugreek" "pepper" "onion" ...
..$ 19: chr "butter" "cheese" "wheat" "ham"