I would like to put the output from a summary command into a data table. For example, with this data frame:
Person V1 V2 V3 V4
1 A medium medium medium high
2 B medium medium low low
3 V high high medium medium
4 D medium medium low high
5 E high high medium low
6 F medium medium low low
7 G high high low high
8 H medium low medium low
9 I medium medium low medium
10 J medium low medium low
x.df<-structure(list(Person = structure(c(1L, 2L, 10L, 3L, 4L, 5L,
6L, 7L, 8L, 9L), .Label = c("A", "B", "D", "E", "F", "G", "H",
"I", "J", "V"), class = "factor"), V1 = structure(c(2L, 2L, 1L,
2L, 1L, 2L, 1L, 2L, 2L, 2L), .Label = c("high", "medium"), class = "factor"),
V2 = structure(c(3L, 3L, 1L, 3L, 1L, 3L, 1L, 2L, 3L, 2L), .Label = c("high",
"low", "medium"), class = "factor"), V3 = structure(c(2L,
1L, 2L, 1L, 2L, 1L, 1L, 2L, 1L, 2L), .Label = c("low", "medium"
), class = "factor"), V4 = structure(c(1L, 2L, 3L, 1L, 2L,
2L, 1L, 2L, 3L, 2L), .Label = c("high", "low", "medium"), class = "factor")), .Names = c("Person",
"V1", "V2", "V3", "V4"), class = "data.frame", row.names = c(NA,
-10L))
with summary(x.df) I get the counts for each factor level:
Person V1 V2 V3 V4
A :1 high :3 high :3 low :5 high :3
B :1 medium:7 low :2 medium:5 low :5
D :1 medium:5 medium:2
E :1
F :1
G :1
(Other):4
Ideally, I would like a data frame of the counts for each factor level, ie:
Var low medium high
1 V1 0 7 3
2 V2 2 5 3
3 V3 5 5 0
4 V4 5 2 3
with row sums equal to the 10.
Here is a method of getting counts of each question variable into a matrix.
myMat <- sapply(x.df[-1],
function(x) table(factor(x, levels=c("low", "medium", "high"))))
The idea is to use sapply to run through each of these variables, convert the variable to a factor with the desired levels, and then call table on the converted variable.
This returns
myMat
V1 V2 V3 V4
low 0 2 5 5
medium 7 5 5 2
high 3 3 0 3
If you want to convert it to your desired output, just use t to transpose it:
t(myMat)
low medium high
V1 0 7 3
V2 2 5 3
V3 5 5 0
V4 5 2 3