On Fri, 28 Aug 2009, Sherlock Ric wrote:
> I'm not convinced that this solution meets the spec given for the RosettaCode 
> problem "Basic bitmap storage"
> http://rosettacode.org/wiki/Basic_bitmap_storage
> 
>    allocimg=:  0 $~ 3 ,~ ]
>    fillimg=: ]`(a:"_)`[}
>    setpix=: (1&{::@])`([: <@;/ <:@(0&{::@]))`[}
>    getpix=: <@;/@:<:@] { [
> 
>    myimg=: allocimg 10 7           NB. 10 by 7 pixel image
>    myimg=: myimg fillimg 0 255 0   NB. fill with green
>    myimg getpix 4 5                NB. get color of pixel from 4th row and 
> 5th col
> 0 255 0
>    myimg=: myimg setpix 4 5; 255 0 255  NB. set pixel to magenta
>    myimg getpix 4 5                NB. verify
> 255 0 255
> 

I guess if myimg is on the rhs of verb, then it will not require
additional ~ in verb train such as

   ....  setpix~  0 255 0  fillimg~  allocimg 10 7

-- 
regards,
====================================================
GPG key 1024D/4434BAB3 2008-08-24
gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

Reply via email to