This is a helper function for many *_byname functions.
Arguments
- a
A matrix or list of matrices.
- vector_arg
The vector argument over which to apply a calculation.
Details
It is potentially ambiguous to specify a vector or matrix argument, say, margin = c(1, 2) when applying
the *_byname functions to unary list of a.
Rather, one should specify, say, margin = list(c(1, 2))
to avoid ambiguity.
If a is a list,
vector_arg is not a list and has length > 1 and length not equal to the length of a,
this function returns a list value for vector_arg.
If a is not a list and vector_arg is a list,
this function returns an un-recursive, unlisted version of vector_arg.
Note that if vector_arg is a single matrix, it is automatically enclosed by a list when a is a list.