For your particular case, since ". is rank-1, it is sufficient to coerce
result from it to rank-1 so that the assembled will be rank-2.
,@". ":i.3 1
0
1
2
,@". ":i.3 2
0 1
2 3
4 5
mar, 06 Apr 2010, Ian Clark skribis:
> I was afraid that would be the answer.
>
> The inconvenience to my code is negligible. It just needs one more
> line, with an (if.) in it. What distresses me is my failure to
> understand why it happens. It makes me suspicious of my whole
> data-storage approach.
>
> I need to store a 2-D integer array, call it z, in an ascii text file
> and recover it on reloading the file.
> Suppose 'a b'=:$z
> Proviso: z is one of several arrays of mixed data. I want to retain a
> visual check on the file contents that they all match-up by rows
> (numbered: i.a). Without this proviso, a sensible thing to do is to
> store the contents of z as a vector and reconstruct it from a
> knowledge of the number of rows, (a).
> Taking a simple minded approach, however, I can use (":) to stuff z in
> a file, and (".) to recover it again from the (2-D) file image. This
> seems adequate and reliable provided a>1 and b>1. I just wouldn't have
> anticipated it breaking down for b=1, which is not an uncommon case to
> arise.
>
> Clearly this is not the approach an experienced J-er would take, and
> I'd like to know what that is.
>
> I don't want to drag this thread off-topic. It just seemed related in
> my mind to the problem of predicting the number of display-lines in z
> -- or do I mean (":z)? Or (". ":z)?
>
> Ian
>
>
> On Tue, Apr 6, 2010 at 12:29 AM, Roger Hui <[email protected]> wrote:
> [---=| TOFU protection by t-prot: 55 lines snipped |=---]
--
regards,
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