Thanks very much.  Useful in learning S:

There is a big savings in the full round trip in j764 but no difference in j632

   , each / 2 test  /\ |: <"0  S:1[ 1 2 3 4 ; 5 6 7 8 ; <'a';'b';'c';'d'
┌─────┬──────┬───────┐
│1 2 3│6 8 10│┌─┬─┬─┐│
│     │      ││a│b│c││
│     │      │└─┴─┴─┘│
└─────┴──────┴───────┘

   10 ts ', each / 2 test  /\ |: <"0  S:0 (i.1e4);(i.1e4);(i.1e4)'
12.3561/sec 10.194MB
    10 ts ',~ each each/ 2 test  each/\ <"1 &.|: > <"0 each 
(i.1e4);(i.1e4);(i.1e4)'
3.50359/sec 12.8865MB



but overall, its good advice that any data that will be used in a calculation 
should be coded as a number, and if you want to scan through a table, keep that 
(calc dependent) section of it unboxed.

----- Original Message -----
From: R.E. Boss <[email protected]>
To: [email protected]
Cc: 
Sent: Friday, October 11, 2013 11:46:43 AM
Subject: Re: [Jprogramming] Scanning (/ or looping) records of an inverted      
table

Your solution could be shortened a bit to

   <"1|:<"0  S:1[ 1 2 3 4 ; 5 6 7 8 ; <'a';'b';'c';'d'
+---------+---------+---------+---------+
|+-+-+---+|+-+-+---+|+-+-+---+|+-+-+---+|
||1|5|+-+|||2|6|+-+|||3|7|+-+|||4|8|+-+||
|| | ||a|||| | ||b|||| | ||c|||| | ||d|||
|| | |+-+||| | |+-+||| | |+-+||| | |+-+||
|+-+-+---+|+-+-+---+|+-+-+---+|+-+-+---+|
+---------+---------+---------+---------+
  

R.E. Boss

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> -----Original Message-----
> From: [email protected] [mailto:programming-
> [email protected]] On Behalf Of Pascal Jasmin
> Sent: vrijdag 11 oktober 2013 15:48
> To: [email protected]
> Subject: [Jprogramming] Scanning (/ or looping) records of an inverted table
> 
> with 4 row 3 column inverted table
> 
>    1 2 3 4 ; 5 6 7 8 ; <'a';'b';'c';'d'
> ┌───────┬───────┬─────────┐
> │1 2 3 4│5 6 7 8│┌─┬─┬─┬─┐│
> │       │       ││a│b│c│d││
> │       │       │└─┴─┴─┴─┘│
> └───────┴───────┴─────────┘
> 
> is there a way to scan through each record without doing this:
> 
>    <"1 &.|: > <"0 each 1 2 3 4 ; 5 6 7 8 ; <'a';'b';'c';'d'
> ┌─────────┬─────────┬─────────┬─────────┐
> │┌─┬─┬───┐│┌─┬─┬───┐│┌─┬─┬───┐│┌─┬─┬───┐│
> ││1│5│┌─┐│││2│6│┌─┐│││3│7│┌─┐│││4│8│┌─┐││
> ││ │ ││a││││ │ ││b││││ │ ││c││││ │ ││d│││
> ││ │ │└─┘│││ │ │└─┘│││ │ │└─┘│││ │ │└─┘││
> │└─┴─┴───┘│└─┴─┴───┘│└─┴─┴───┘│└─┴─┴───┘│
> └─────────┴─────────┴─────────┴─────────┘
> 
> I was hoping for some version/combination of L: S: but I can't say I
> understand S:
> 
>   test =. 4 : 'a;b;<c [b=. b+ a [''a b c'' =. x'
>     2 test  each/\ <"1 &.|: > <"0 each 1 2 3 4 ; 5 6 7 8 ; <'a';'b';'c';'d'
> ┌─────────┬─────────┬──────────┐
> │┌─┬─┬───┐│┌─┬─┬───┐│┌─┬──┬───┐│
> ││1│6│┌─┐│││2│8│┌─┐│││3│10│┌─┐││
> ││ │ ││a││││ │ ││b││││ │  ││c│││
> ││ │ │└─┘│││ │ │└─┘│││ │  │└─┘││
> │└─┴─┴───┘│└─┴─┴───┘│└─┴──┴───┘│
> └─────────┴─────────┴──────────┘
> 
> 
> 
> Maybe  <"1 &.|: > <"0 each is actually really good?
> ----------------------------------------------------------------------
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