I'd say forget the binary representation.
The primitives, namely ;: u;.n u\ u\. u/. produce lists even when there
is only one item in the partition. Very regular.
The anomalous case stems from simple old keyboard entry. You ran into
trouble from
'a';'bcd'
because 'a' creates an atom, while 'bcd' creates a list. You have to
become sensitized to this. There's just something special about a
single character or a single number: they are atoms.
You would have the same problem with
1 ; 2 3 4
1 is an atom; 2 3 4 is a list.
It's like learning to run IEHIOSUP after changing an SVC: after you get
burned enough you stop making that mistake.
Henry Rich
On 1/19/2014 10:59 PM, Joe Bogner wrote:
Roger & Henry - Thank you for the explanations
I had a feeling that the arrays were structurally different but I
couldn't figure out how to tell.
I also narrowed it down to my use of cut. I will study that to
understand further
These were the ways I tried to look before
]a=:('a';'bcd')
┌─┬───┐
│a│bcd│
└─┴───┘
]b=:(' ' cut 'a bcd')
┌─┬───┐
│a│bcd│
└─┴───┘
$ a
2
$ b
2
Other clues that they were different
$ each a
┌┬─┐
││3│
└┴─┘
$ each b
┌─┬─┐
│1│3│
└─┴─┘
I guess this would be the ultimate test -- the binary representation
* (manually removed the last one from the first column that was filled)
(<(19 $ (3!:3 a))),.<(3!:3 b)
┌────────┬────────┐
│e1000000│e1000000│
│20000000│20000000│
│02000000│02000000│
│01000000│01000000│
│02000000│02000000│
│1c000000│1c000000│
│30000000│34000000│
│e1000000│e1000000│
│02000000│02000000│
│01000000│01000000│
│00000000│01000000│
│61000000│01000000│
│e1000000│61000000│
│02000000│e1000000│
│03000000│02000000│
│01000000│03000000│
│03000000│01000000│
│62636400│03000000│
│ │62636400│
└────────┴────────┘
Is there an easier way to visualize or identify the difference?
words also creates a 1 rank boxed string and can't be compared with <'a'
(<'a') i. (;: 'a b c a')
1 1 1 1
Henry's suggestion works:
(<,'a') i. (;: 'a b c a')
0 1 1 0
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