Data Frames

Usage

data.frame(..., row.names = NULL, check.rows = FALSE,
        check.names = TRUE)

as.data.frame(x)
is.data.frame(x)

row.names(data.frame.obj)
row.names(data.frame.obj) <- names
print(data.frame.obj, ..., digits = NULL, quote = FALSE, right = TRUE)
plot (data.frame.obj, ...)

Arguments

... these arguments are of either the form value or tag=value. Component names are created based on the tag (if present) or the deparsed argument itself.
row.names a character vector giving the row names for the data frame.
check.rows if TRUE then the rows are checked for consistency of length and names.
check.names if TRUE then the names of the variables in the data frame are checked to ensure that they are valid variable names. If necessary they are adjusted (by make.names) so that they are.
data.frame.obj objects of class data.frame.
... optional arguments to print or plot methods.

Value

For data.frame(.) a data frame. Data frames are the fundamental data structure used by most of R's modeling software. They are tightly coupled collections of variables which share many of the properties of matrices. The main difference being that the columns of a data frame may be of differing types (numeric, factor and character).

as.data.frame is generic function with many methods. It attempts to coerce its argument to be a data frame.

is.data.frame returns TRUE if its argument is a data frame and FALSE otherwise.

row.names can be used to set and retrieve the row names of a data frame, similarly to rownames for arrays.

plot.data.frame, a method of the plot generic, uses stripplot for one variable, plot.default (scatterplot) for two variables, and pairs (scatterplot matrix) otherwise.

For the print method (print.data.frame), see print.matrix.

xpdrows.data.frame is an auxiliary function which expands the rows of a data frame. It is used by the data frame methods of [<- and [[<- (which perform subscripted assignments on a data frame), and not intended to be called directly.

See Also

read.table, Math.data.frame,etc, about Group methods for data.frames; make.names.

Examples

L3 <- LETTERS[1:3]
str(d <- data.frame(cbind(x=1, y=1:10), ch=sample(L3, 10, repl=TRUE)))
str(     data.frame(cbind(  1,   1:10),    sample(L3, 10, repl=TRUE)))
is.data.frame(d)
all(1:10 == row.names(d))# TRUE (coercion)


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