Apply a Function to a Margin of an Array
Description
High performance variant of apply() for a fixed set of functions.
Considerable speedup of this implementation is a trade-off for universality: user defined
functions cannot be used with this package. However, about 20 most currently employed
functions are available for usage. They can be divided in three types:
reducing functions (like mean(), sum() etc., giving a scalar when applied to a vector),
mapping function (like normalise(), cumsum() etc., giving a vector of the same length
as the input vector) and finally, vector reducing function (like diff() which produces
result vector of a length different from the length of input vector).
Optional or mandatory additional arguments required by some functions
(e.g. norm type for norm()) can be
passed as named arguments in '...'.