[Jprogramming] Consecutive Numbers in List

[Marshall Lochbaum]

If I'm translating the code to English, I prefer the second, without "apply"
because there's a more direct correspondence between words in J and English
words--J has no real "apply" verb.
In a comment for the code I gave, I would probably say the first so that
it's clear that we want the result of the application rather than the verb
itself.
An appropriate translation of the code could also be "+/ on prefixes of
suffixes of the first four primes."

It is an excellent demonstration of those adverbs--I'm glad you showed it
off.

Marshall

On Fri, Sep 23, 2011 at 10:36 PM, Roger Hui <rhui000 at shaw.ca> wrote:

> Marshall, I am curious:  which of the following
> two statements do you think is better?
>
> Apply +/ on prefixes of suffixes
> +/ on prefixes of suffixes
>
> p.s. I showed your solution at the Minnowbrook
> conference here this week.
>
>
>
> ----- Original Message -----
> From: Marshall Lochbaum <mwlochbaum at gmail.com>
> Date: Friday, September 16, 2011 10:44
> Subject: Re: [Jprogramming] Consecutive Numbers in List
> To: Programming forum <programming at jsoftware.com>
>
> >    ; <@:(+/\)\. p:i.4
> > 2 5 10 17 3 8 15 5 12 7
> >
> > applies +/ on prefixes of suffixes.
> >
> > Marshall
> >
> > On Fri, Sep 16, 2011 at 12:59 PM, Roger Hui <rhui000 at shaw.ca>
> > wrote:
> > > Multiple applications of the infix x +/\ y does the trick.
> > >
> > >   f=: >:@i.@# +/\&.>  <
> > >   f 2 3 5 7
> > > ┌───────┬──────┬─────┬──┐
> > > │2 3 5 7│5 8 12│10 15│17│
> > > └───────┴──────┴─────┴──┘
> > >   g=: ;@f
> > >   g 2 3 5 7
> > > 2 3 5 7 5 8 12 10 15 17
> > >
> > > The results of f are the 1-, 2-, 3-, and 4-infix sums.
> > > Razing the whole thing gets the desired result.
> > >
> > >
> > >
> > > ----- Original Message -----
> > > From: David Vaughan <purpleblues13 at googlemail.com>
> > > Date: Friday, September 16, 2011 9:49
> > > Subject: [Jprogramming] Consecutive Numbers in List
> > > To: Programming forum <programming at jsoftware.com>
> > >
> > > > I'm trying to get a list of the sum of all possible consecutive
> > > > numbers.
> > > > E.g.
> > > >
> > > > for p:i.4, I want a list:
> > > >
> > > > 2 0 0 0
> > > > 2 3 0 0
> > > > 2 3 5 0
> > > > 2 3 5 7
> > > > 3 5 7 0
> > > > 5 7 0 0
> > > > 7 0 0 0
> > > > 3 5 0 0
> > > >
> > > > I then do +/"1 to get the sum of each row. My problem is that
> > > > I'm only getting consecutive numbers that start on p:0 or
> > end on
> > > > the last value, so it misses out loads in between. In the
> > > > example above I get all but the last row. This is what I
> > have so far:
> > > >
> > > >    list=:3 :'(+/"1@>{\p:i.y),+/"1@>{\.p:i.y'
> > > >    list 10
> > > > 2 5 10 17 28 41 58 77 100 129 129 127 124 119 112 101 88 71
> > 52 29
> > > >
> > > > Also I was wondering if there was a way to streamline something
> > > > like that because I'm doing +/"1@>{\.p:i.y twice basically, but
> > > > with \. changed to \
>
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