it still feels like a stretch, but your point of growing a data structure is
fair.
These seem hard to understand though.
(i.0) $2
2
'' $ 2 3
2
----- Original Message ----
From: Devon McCormick <[EMAIL PROTECTED]>
To: Programming forum <[email protected]>
Sent: Tuesday, October 24, 2006 8:38:45 PM
Subject: Re: [Jprogramming] Words cell format -- shape of an atom
It's a paradox only if you consider consistency to be paradoxical - which it
is for most programming languages.
Consider that a 2-dimensional array can be extended along 2 axes:
a2=. 1 1$1
a2;(a2,1);a2,.1
+-+-+---+
|1|1|1 1|
| |1| |
+-+-+---+
Analogously, a 1-dimensional array can be extended only along 1 axis:
a1=. 1$1
a1;(a1,1);a1,.1
+-+---+---+
|1|1 1|1 1|
+-+---+---+
Finally, a 0-dimensional array cannot be extended along any axis
because it does not have any axes. When it is concatenated with
something, it is no longer a scalar (0-dimensional array).
Another way of putting this is that the result of $ is always a vector:
for a 2-dimensional array, it is a vector of length 2; for a 1-dimensional
array it is a vector of length 1; and for a 0-dimensional array it is a
vector of length 0.
The usefulness of this consistency can be seen by understanding
that we can predict the shape of 2 arrays compared orthogonally (all
elements to all elements) by simply adding the shapes of the 2 arrays:
$(2 3 4$1) =/ 5 6$1
2 3 4 5 6
#$((5$1)$1) =/ (2$1)$1 NB. 5+2 = 7
7
#$((5$1)$1) =/ (1$1)$1 NB. 5+1 = 6
6
#$((5$1)$1) =/ (0$1)$1 NB. 5+0 = 5
5
1-:(0$1)$1
1
On 10/24/06, Miller, Raul D <[EMAIL PROTECTED]> wrote:
>
> Pascal Jasmin wrote:
> > why the shape of an atom isn't 1 is the paradox :)
>
> --
Devon McCormick
^me^ at acm.
org is my
preferred e-mail
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