T2=: [:($$ [:+/\ ,) (1, }:~: }.)"1
[;/'H V'=: (*"_ _1 T2,: T2&.|:) tst1
NB. hor. & vert. connected 1's
+-----------------+---------------+
| 0 0 0 2 2 2|0 0 0 16 21 26|
| 0 0 0 0 0 0|0 0 0 0 0 0|
| 4 4 4 0 0 0|2 7 12 0 0 0|
| 0 0 0 7 7 7|0 0 0 18 23 28|
| 0 0 0 9 9 9|0 0 0 18 23 28|
|10 10 10 0 0 0|4 9 14 0 0 0|
|12 12 12 0 0 0|4 9 14 0 0 0|
|14 14 14 14 14 14|4 9 14 20 25 30|
|15 15 15 15 15 15|4 9 14 20 25 30|
|16 16 16 16 16 16|4 9 14 20 25 30|
| 0 0 0 18 18 18|0 0 0 20 25 30|
| 0 0 0 20 20 20|0 0 0 20 25 30|
+-----------------+---------------+
rpl=:] - (-/ , 0:)@[ {~ [EMAIL PROTECTED] i. ]
NB. Millers solution in
NB. http://www.jsoftware.com/pipermail/programming/2007-July/007303.html
V ( [EMAIL PROTECTED] $]) i.~@,.&,/ (([:(,:|.) ,"_1) rpl"_1 ])H,:~V
NB. indicating blocks of 1's
0 0 0 3 3 3
0 0 0 0 0 0
12 12 12 0 0 0
0 0 0 21 21 21
0 0 0 21 21 21
30 30 30 0 0 0
30 30 30 0 0 0
30 30 30 45 45 45
30 30 30 45 45 45
30 30 30 45 45 45
0 0 0 63 63 63
0 0 0 63 63 63
[R=: V ([ (,:&, rpl [) [EMAIL PROTECTED] $]) i.~@,.&,/ (([:(,:|.) ,"_1)
rpl"_1 ])H,:~V
NB. less blocks, but if H is used as LHS, answer is wrong ...
0 0 0 3 3 3
0 0 0 0 0 0
12 12 12 0 0 0
0 0 0 21 21 21
0 0 0 21 21 21
30 30 30 0 0 0
30 30 30 0 0 0
30 30 30 45 45 45
30 30 30 45 45 45
30 30 30 45 45 45
0 0 0 45 45 45
0 0 0 45 45 45
([:([,: (-~>:))/"_1 $#: (](i.}.@,. i:) 0~.@,])@,) R
0 3
1 3
2 0
1 3
3 3
2 3
5 0
5 3
7 3
5 3
R.E. Boss
> -----Oorspronkelijk bericht-----
> Van: [EMAIL PROTECTED] [mailto:programming-
> [EMAIL PROTECTED] Namens Sherlock, Ric
> Verzonden: woensdag 11 juni 2008 14:45
> Aan: Programming forum
> Onderwerp: [Jprogramming] Finding blocks in a table/matrix
>
> Below is a problem that I have enjoyed working on that stems from an
> attempt to generalise the writing of a boxed table of mixed type to an
> Excel worksheet.
>
> My attempt at a solution in the script at the bottom gives a non-optimal
> answer (it only finds blocks within rows) that I'd like to improve if
> possible/practical.
>
> tsta is a boxed table(matrix) of mixed numeric and literal type
>
> ischar=: 3!:0 e. 2 131072"_
> tst1=: ischar &> tsta NB. Mask of boxed literals in tsta
>
> NB. Below is an example tst1 for copying into a session.
> tst1=: _99&".;._2 (0 : 0)
> 0 0 0 1 1 1
> 0 0 0 0 0 0
> 1 1 1 0 0 0
> 0 0 0 1 1 1
> 0 0 0 1 1 1
> 1 1 1 0 0 0
> 1 1 1 0 0 0
> 1 1 1 1 1 1
> 1 1 1 1 1 1
> 1 1 1 1 1 1
> 0 0 0 1 1 1
> 0 0 0 1 1 1
> )
>
> The problem is to specify the blocks of ones in the table.
> A block is specified by the position of its top left member and its shape.
>
> Below is an example desired output of a verb "blocks" for tst1:
> blocks tst1
> 0 3 NB. topleft of block
> 1 3 NB. shape of block
>
> 2 0
> 1 3
>
> 3 3
> 2 3
>
> 5 0
> 5 3
>
> 7 3
> 5 3
>
> $blocks tst1
> 5 2 2
>
> Obviously there are other ways to organise the blocks of ones in tst1. A
> solution is correct as long as all ones in tst1 are included in one and
> only one block. Solutions that produce fewer blocks are better provided
> they don't take much longer to find the minimum number of blocks.
>
> tst2=: 5 [EMAIL PROTECTED] NB. Another example table of 0s & 1s that blocks
> should
> work with
>
>
>
> NB.========Start of Script======================================
> ischar =: 3!:0 e. 2 131072"_
> firstones=: > 0: , }: NB. Mask of first ones
>
> tlcols=: <@[EMAIL PROTECTED]"1 NB. leftmost columns of blocks of 1s
> toplefts=: i.@:# ,.&.> tlcols NB. topleft index of blocks of 1s
>
> bytype=: 1 : 'u;.1~ (1, 2~:/\ ])'
> lens=: <@({.bytype # #bytype)"1 NB. lengths of blocks of 1s
> shapes=: 1: ,. &.> lens NB. shapes of blocks of 1s
>
> blocks=: ;@toplefts ,:"1 ;@shapes NB. blocks of 1s
>
> Note 'testing'
> ;toplefts tst1 NB. list of topleft of blocks of 1s
> ;toplefts -.tst1 NB. list of topleft of blocks of 0s
> (;@toplefts ,:"1 ;@shapes) tst1 NB. List of blocks
> ;(toplefts ,:"1 &.> shapes) tst1 NB. Also list of blocks
>
> (blocks ischar &> tsta) <;.0 tsta NB. blocks of char (you will need to
> create a tsta to run this)
> (blocks -.ischar &> tsta) <;.0 tsta NB. blocks of non-char
> )
> NB.=======End of Script==========================================
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
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