The Heading pseudo-function overrides the automatic
heading on the following items in a table.
Usage
Heading(name = NULL)
Arguments
Pseudo-functions
This is a pseudo-function: it takes the form of a function call, but is
never actually called: it is
handled specially by tabular.
Details
This replaces the automatic heading or row label on the following item
with the name or string as specified. If no argument
is given, the heading or label is suppressed.
An alternative form of Heading(name) is (name=...), where
... is an expression to be displayed in the table.