Summary Group Method for Data Frame Objects
DESCRIPTION:
A group method for calculating mathematical summaries for data frame objects.
The method
will generally result in an error unless all the variables in the data frame
are numeric vectors or numeric matrices.
USAGE:
fun(object, ...)
REQUIRED ARGUMENTS:
- object
-
any object for which the relevant function,
fun
, from the Summary group, inherits
from class
"data.frame"
.
OPTIONAL ARGUMENTS:
- ...
-
any optional arguments to the relevant generic function.
VALUE:
a single value, the result of applying the summary to all the values of
all the variables in
object
.
This is a group method for the functions of the
Summary
group (
sum()
,
prod()
,
any()
, etc), which are essentially all functions that return a single
numerical numeric or logical summary of their (numeric or logical) argument.
This method will generally result in an error unless all the variables in
the data frame are numeric vectors or numeric matrices.
EXAMPLES:
# find the maximum of all the non-factors in a data frame
max(wafer[, sapply(wafer, function(x) !inherits(x,"factor"))])