BUILT-IN WOLFRAM LANGUAGE SYMBOL
requires expr to be a full array with a depth that matches the pattern patt.
requires also that test yield True when applied to each of the array elements in expr.
- In a full array all parts at a particular level must be lists of the same length.
- ArrayQ[expr,1|2] tests whether expr is either a vector or a matrix.
- ArrayQ[expr,_,NumberQ] tests whether expr is a numerical array at all levels.
A vector of numbers is a full array:
A vector in which one element is itself a list is not a full array:
A ragged collection of nested lists is not a full array: