as.data.frame
Construct a Data Frame Object from an S object

Description

All as.data.frame() functions are S3 method implementations of the as.data.frame generic for the various object classes. Each method creates a data frame according to the arguments.

Usage

as.data.frame(x, row.names = NULL, optional = FALSE, ...)
as.data.frame.model.matrix(x, row.names = NULL, optional = FALSE, ...)

Arguments

x an S object.
row.names the row names of the data frame.
optional a logical value. (This argument is not available in the default and character class methods).
  • If TRUE, keep the object default column names with no change.
  • If FALSE (the default), try to construct the column names with a specified nm argument(if available) or the names of x (if available). Otherwise, construct the column names as a "X*", "V*", or "c*" format. (* can be 1, 2, 3, ..., or combination of character elements).

Details

In as.data.frame.model.matrix method, if optional = FALSE, the row name of x will be deparsed.
Value
returns a data frame, depending on the arguments. If x is already a data frame, the value is a data frame like x, except that any classes preceding "data.frame" are dropped, so that "data.frame" becomes the first class.
References
Chambers, J. M. (1992) Data for models. Chapter 3 of Statistical Models in S eds J. M. Chambers and T. J. Hastie, Wadsworth & Brooks/Cole.
See Also
Date, POSIXt, difftime
Examples
# For class raw, factor, ordered, integer, numeric, complex, logical 
# and vector:
x <-  c(1:3)
as.data.frame(x, row.names = c("one", "two", "three"), 
   optional = FALSE, nm = c("Data"))
##           Data
##  one      1
##  two      2
##  three    3

as.data.frame(x, row.names = c("one", "two", "three"), 
   optional = TRUE, nm = c("Data"))
##           structure(c("1", "2", "3"), class = "AsIs")
##   one                                             1
##   two                                             2
##   three                                           3

# For class character
x <- c("Red", "Green", "Blue") 
as.data.frame(x, row.names = c("R1", "R2", "R3"))
##         x
##  R1   Red
##  R2 Green
##  R3  Blue

y <- as.data.frame(x, row.names = c("R1", "R2", "R3"),
   stringsAsFactors = FALSE) 
class(y$x)     #   Strings is not converted as factors 
##  [1] "character"

y <- as.data.frame(x, row.names = c("R1", "R2", "R3"),
   stringsAsFactors = TRUE) 
class(y$x)    #    Strings is converted as factors
##   [1] "factor"

# For class matrix
y <- matrix(1:12, nrow = 3)
as.data.frame(y, row.names = c("One", "Two", "Three"))
##        V1 V2 V3 V4
##  One    1  4  7 10
##  Two    2  5  8 11
##  Three  3  6  9 12

# For class list
aa <- 1:3
bb <- c("R", "G", "B")
cc <- list(aa, bb)
as.data.frame(cc)
##     X1.3          c..R....G....B..
## 1    1                R
## 2    2                G
## 3    3                B
as.data.frame(cc, optional = TRUE)
##    1:3        c("R", "G", "B")
## 1   1                R
## 2   2                G
## 3   3                B

# For class table
y <- matrix(1:12, nrow = 3)
z <- as.table(y)
as.data.frame(z)
##     Var1 Var2 Freq
## 1     A    A    1
## 2     B    A    2
## 3     C    A    3
## 4     A    B    4
## 5     B    B    5
## 6     C    B    6
## 7     A    C    7
## 8     B    C    8
## 9     C    C    9
## 10    A    D   10
## 11    B    D   11
## 12    C    D   12

# For class ts
as.data.frame(ts(3:5), row.names = c("I", "II", "III"))
##     x
## I   3
## II  4
## III 5

# For class POSIXlt
plt <- as.POSIXlt(c("1970-01-01 00:00:00", "2038-01-19 03:14:07"))
as.data.frame(plt, row.names = c("Unix Epoch", "Unix Millennium Bug"))
##                                     plt
## Unix Epoch          1970-01-01 00:00:00
## Unix Millennium Bug 2038-01-19 03:14:07

# For class difftime
dt <- as.difftime(c("01:00:00", "00:01:00", "00:00:01"))
as.data.frame(dt)
##          dt
## 1 3600 secs
## 2   60 secs
## 3    1 secs

# For class data.frame
x <- data.frame(matrix(1 : 12, 3)) 
# add some classes preceding "data.frame"
class(x) <- c("foo1", "foo2", "data.frame")  
class(as.data.frame(x))
## [1] "data.frame"

# default
x  <- 3
class(x) <- "other"
## Not run: 
as.data.frame(x)
## Error in as.data.frame.default(x) : 
##   cannot coerce class "other" into a data.frame

## End(Not run)

# For class model.matrix
fw <- lm(Fuel ~ Weight, data = Sdatasets::fuel.frame)
mm.y <- model.matrix(fw)
as.data.frame.model.matrix(mm.y)
##                               mm.y.(Intercept) mm.y.Weight
## Eagle Summit 4                               1        2560
## Ford Escort 4                                1        2345
## Ford Festiva 4                               1        1845
##     .
##     .
##     .
## Nissan Van 4                                 1        3690
Package base version 4.0.0-28
Package Index