CONCAT/APPEND/PREPEND CAS FUNCTION

[Tim Wessman]

(08-01-2016 11:40 PM)compsystems Wrote:  [
[a,b],
[c,d],
[1],[2]
] this is a matrix? not

No, it is not. That is a vector of 2, two length vectors, and a two one item vectors.

Quote:dim(prepend(mat1,vec1)) [Enter] returns [3,2] ??? Contradiction

No, it isn't. You have 3 items, with a maximum size of 2 in the other direction. That does not mean you can't have fewer then 2 in a specific position. The CAS does not have a "matrix" object. It only has vectors that can contain other objects. A "matrix" is a vector of equal length vectors. Anything else is simply a vector of assorted objects.

You are correct that the 2D editor does not support this type of entry. This is by design due the two simple facts that a) there are not really any direct uses for this type of object in the various math commands - it is only really useful during programming and b) to support it would mean making the 2D editor allow this type of input which is detrimental to nearly every single user.