I've "tidied up" your algorithm below. Thanks again!
NB. running sum of starts of connected 1s in each row
incgrp=: [:($$ [:+/\ ,) (1, }:~: }.)"1
rpl=: ] - (-/ , 0:)@[ {~ [EMAIL PROTECTED] i. ] NB. numeric replace (RMiller)
hv=: *"_ _1 incgrp,: incgrp&.|: NB. hor. & vert. connected 1s.
rplhv=: (([:(,:|.) ,"_1) rpl"_1 ]) @: hv
rectgrps=: ([EMAIL PROTECTED]([EMAIL PROTECTED] $ ]) i.~@,.&,/) @: rplhv NB.
rectangular groups of 1s
NB. topleft and bottomright corners of each group
tlbr=: ($#: (](i.}.@,. i:) 0~.@,])@,) @: rectgrps
blocks2=: ([,: (-~>:))/"_1 @: tlbr NB. Topleft and shape of each group
blocks2 tst1
0 3
1 3
2 0
1 3
3 3
2 3
5 0
5 3
7 3
3 3
10 3
2 3
---R.E. Boss wrote:
> T2=: [:($$ [:+/\ ,) (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==========================================
> >
> ----------------------------------------------------------------------
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> http://www.jsoftware.com/forums.htm
>
> ----------------------------------------------------------------------
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