Use print() on a by object

DESCRIPTION:

print.by prints an object of class by, which is produced by the by function. Before each element of the object it prints the combination of factor levels the object represents, using information in dimnames(x) and names(dimnames(x)), then it prints the element itself, using the print method for that element. It also prints a separator line between elements of the by object.

USAGE:

print.by(x, ..., vsep = <<See below>>) 

REQUIRED ARGUMENTS:

x
The by object to print, typically produced by the by() function.

OPTIONAL ARGUMENTS:

...
Arguments passed onto the print methods used to print the elements of x.
vsep
The vertical separator, printed before all but the first elements of x. The default is a sequence of dashes 3/4 the width of the page (.Options$width) followed by a carriage return.