On Fri, Jul 15, 2011 at 2:43 PM, Devon McCormick <[email protected]> wrote:
> On Fri, Jul 15, 2011 at 9:14 AM, Simon Clarkstone 
> <[email protected]> wrote:
[...]
>> Related: is there a conventional way to convert between ravelled and
>> non-ravelled indexes, for a given array shape?  I would rather not do
>> it in 20 characters if I could do it in 5.
[...]
>   ]ixs=. ('.'=,aa)#i.$,aa
> 2 3 4 8 10 11 24
>   $ixs=. ($aa)#:('.'=,aa)#i.$,aa
> 7 2
>   ixs
> 0 2
> 0 3
> 0 4
> 1 3
> 2 0
> 2 1
> 4 4

Thanks, the base and anti-base operators are just what I was looking
for; I don't know how I missed them.  (I mostly learnt what I know so
far by starting with some operators mentioned in tutorials and reading
about everything I needed to understand the example code for them.)  I
suppose that I should have guessed there would be operators for that,
given that there are operators like Anagram and Anagram Index.

-- 
src/
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

Reply via email to