This function converts an xtabs object to a matrix.
Usage
## S3 method for class 'xtabs':
as.matrix(x, ...)
Arguments
x
an object of class xtabs
...
additional arguments to be passed to or from methods.
Details
xtabs is indeed already a matrix, but won't be converted to a pure matrix by as.matrix.default function, as its classes will remain unchanged. Some functions expecting a pure matrix may fail, when fed with a xtabs object.
This function will only kill the classes and the call attribute.
Note that unclass would as well discard the classes xtabs and table, but retain the "call" attribute.