Bill Lam has it right. Here is the example:
a=: i. 3 4 5
2 3 3&{"0 1 a
2 3 3
7 8 8
12 13 13
17 18 18
22 23 23
27 28 28
32 33 33
37 38 38
42 43 43
47 48 48
52 53 53
57 58 58
2 3 3&({"0 1) a
2 7 12 17
23 28 33 38
43 48 53 58
This is mind-bending the first time you see it, but it's worth working
through. It is a good example of the subtlety of rank.
Henry Rich
Bill Harris wrote:
>> -----Original Message-----
>> From: [email protected] [mailto:programming-
>> [email protected]] On Behalf Of Henry Rich
>> Sent: Friday, May 29, 2009 5:00 AM
>> To: Programming forum
>> Subject: Re: [Jprogramming] A from ({) question
>>
>> To pull different columns from different tables, use
>>
>> columnlist {"0 2 a
>>
>> or
>>
>> columnlist {"_1 a
>
> Henry,
>
> Okay, I'm stumped. What you suggests works nicely, but I can't figure
> out how to put it in a pro-verb. That is,
>
> ]a=: i. 3 4 5
> 0 1 2 3 4
> 5 6 7 8 9
> 10 11 12 13 14
> 15 16 17 18 19
>
> 20 21 22 23 24
> 25 26 27 28 29
> 30 31 32 33 34
> 35 36 37 38 39
>
> 40 41 42 43 44
> 45 46 47 48 49
> 50 51 52 53 54
> 55 56 57 58 59
> 2 3 3 {"0 1 a
> 2 7 12 17
> 23 28 33 38
> 43 48 53 58
> selcol=: 2 3 3 & {"0 1
> selcol a
> 2 3 3
> 7 8 8
> 12 13 13
> 17 18 18
>
> 22 23 23
> 27 28 28
> 32 33 33
> 37 38 38
>
> 42 43 43
> 47 48 48
> 52 53 53
> 57 58 58
>
> Executed as a command, it does exactly what I want. When I try to make
> it into a pro-verb, it does something different, and I don't yet see a
> way back. I know it will be obvious when someone explains it.
>
> Bill
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