Cross tabulation
xtabs
creates a contingency table (optionally a sparse matrix) from
cross-classifying factors, usually contained in a data-frame-like object,
using a formula interface.
NOTE: This man page is for the xtabs
S4 generic function
defined in the BiocGenerics package.
See ?stats::xtabs
for the default method
(defined in the stats package).
Bioconductor packages can define specific methods for objects
not supported by the default method.
xtabs(formula=~., data=parent.frame(), subset, sparse=FALSE, na.action, addNA=FALSE, exclude=if(!addNA)c(NA, NaN), drop.unused.levels=FALSE)
formula, subset, sparse, na.action, addNA, exclude, drop.unused.levels |
See |
data |
A data-frame-like object. |
See ?stats::xtabs
for the value returned by the
default method.
Specific methods defined in Bioconductor packages should also return the type of object returned by the default method.
stats::xtabs
for the default xtabs
method.
showMethods
for displaying a summary of the
methods defined for a given generic function.
selectMethod
for getting the definition of
a specific method.
xtabs,DataFrame-method in the S4Vectors
package for an example of a specific xtabs
method (defined
for DataFrame objects).
BiocGenerics for a summary of all the generics defined in the BiocGenerics package.
xtabs # note the dispatch on the 'data' arg only showMethods("xtabs") selectMethod("xtabs", "ANY") # the default method library(S4Vectors) showMethods("xtabs") ## The xtabs() method for DataFrame objects: selectMethod("xtabs", "DataFrame")
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