Brewer, Andrew:
R.E.,
I've found { kind or useful for working with amend, but keeping the array
structure intact (maybe helpful for amend in-place?)
For example:
indexes =. , @ { @: (i.each) @ $
] a =: 5 9 $ '-'
] b =: ? ($a) $ 2
] a =: '*' ( (,b) # indexes a ) } a
***--***-
**---**--
---*--*--
*-***--**
**-*-****
In this specific case is no need for special 'indexes' verb; i. will do just
fine (with some magic):
'#' ( b #&, i.$ a )"_ } a
----##--#
#-##-##--
###--####
#--#-#-#-
-####---#
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
