Thanks for the pointers, here it is:
  scan =. 1 : '}.@: (((u~/)&.|.)\)'
   - scan >: i.5
_1 _4 _8 _13
   (1-2),((1-2)-3),(((1-2)-3)-4),((((1-2)-3)-4)-5)
_1 _4 _8 _13

Does this seem like something there ought to be a primitive for, I think
that q might have one? Anyway, it looks like it works so far. I want to use
it to do exponentially weighted moving average EWMA, which was a topic on
the forum earlier in the year.

Cheers,
Matthew.

On Fri, Sep 26, 2008 at 5:07 PM, Devon McCormick <[EMAIL PROTECTED]> wrote:

> Hi Matthew - maybe this is what you want:
>
>   (1-2)-3
> _4
>   -~/|.1 2 3
> _4
>   ((1-2)-3)-4
> _8
>   -~/|.1 2 3 4
> _8
>
> so, you could do "f~/|."
>
> On Fri, Sep 26, 2008 at 11:44 AM, Matthew Brand <[EMAIL PROTECTED]
> >wrote:
>
> > Hi All,
> >
> > If I have a dyadic function f, how can I do the following:
> >
> > (((y0 f y1) f y2) f y3... ) f yn
> >
> > I want to feed the result of x f y into the next evaluation as the left
> > parameter.
> >
> >
> > Thanks,
> > Matthew.
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
> >
>
>
>
> --
> Devon McCormick, CFA
> ^me^ at acm.
> org is my
> preferred e-mail
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

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