Dividing a character vector into segments

Question

I have the following vector Vec: ACGTTGCAand I would like to divide it into a nested vector in which at the i-th position there will be a subsegment of Veclength 4, starting from the i-th position Vec.

For example, Vec[(⍳¯3+⍴Vec)∘.+¯1+⍳4]returns:

ACGT
CGTT
GTTG
TTGC
TGCA

But the problem with the above output is that it is a character matrix, while I would like to get the following output:

┌──────────────────────────┐
│┌────┬────┬────┬────┬────┐│
││ACGT│CGTT│GTTG│TTGC│TGCA││
│└────┴────┴────┴────┴────┘│
└──────────────────────────┘

For the next line: the vec←'Hy, only testing segmenting vec into pieces of 4' correct result of what I'm looking for would be:

┌→────────────────────────────────────────┐
│ ┌→───┐ ┌→───┐ ┌→───┐ ┌→───┐             │
│ │Hy, │ │y, o│ │, on│ │ onl│ (and so on) │
│ └────┘ └────┘ └────┘ └────┘             │
└∊────────────────────────────────────────┘

In addition, is there a way to convert such a vector into a single vector in which subsequent lines will contain 4 characters?

Example: for a character symbol, the foobartestingresult is:

foob
ooba
obar
bart
arte
rtes
test
esti
stin
ting

Answer 1

GNU APL, , Dyalog. :

      4 ,/ 'foobartesting'
 foob ooba obar bart arte rtes test esti stin ting

Answer 2

: "split" (↓), , () . , , "" , , , , APL.

Dyalog APL v14.0/64, Intel Core i5 @1.60Ghz:

← 'foobartesting'

(4,/x) 9,3

(↓ 4 {⍵ [(0, ⍳-⍺-⍴⍵) ∘. + ⍳⍺]} x) 2.3

; , 10 000, 10 (7 0,7 ).

DALOG APL "" 1- 2- ; , APL.

Answer 3

, . , :

vec←'Hy, only testing segmenting vec into pieces of 4'

, : -)

⎕ml←3

;-):

      display 4{⍺↑¨(0,⍳(⍴⍵)-⍺)↓¨⊂⍵}'ACGTTGCA'
┌→───────────────────────────────────┐
│ ┌→───┐ ┌→───┐ ┌→───┐ ┌→───┐ ┌→───┐ │
│ │ACGT│ │CGTT│ │GTTG│ │TTGC│ │TGCA│ │
│ └────┘ └────┘ └────┘ └────┘ └────┘ │
└∊───────────────────────────────────┘