Hi Roger,

Thanks.

I'll keep this in my code library.

Much appreciated.

r/Alex

-----Original Message-----
From: [email protected] 
[mailto:[email protected]] On Behalf Of Roger Hui
Sent: Thursday, January 28, 2010 10:45 AM
To: Programming forum
Subject: Re: [Jprogramming] Running Subtraction

   x=: 35.5
   ] y=: 2*5+i.5
10 12 14 16 18
   
   +/\ y                NB. running sums
10 22 36 52 70
   x <. +/\ y           NB. running sums, up to a maximum of x
10 22 35.5 35.5 35.5
   2 -~/\ 0,x <. +/\ y  NB. first differences (deltas) of the above
10 12 13.5 0 0

Another way to look at the first differences, is that
they are the contribution of each element of y 
toward the running sum, up to a maximum of x .



----- Original Message -----
From: Alex Rufon <[email protected]>
Date: Wednesday, January 27, 2010 18:37
Subject: Re: [Jprogramming] Running Subtraction
To: Programming forum <[email protected]>

> I have a question.
> 
> In Rogers code:
> 2-~/\0,x<.+/\y
> 
> I understood that 'x<.+/\y' gives the floor for each value. 
> What I don't get is '2-~/\0,'?
> 
> I would appreciate further clarification. Thanks.
> 
> -----Original Message-----
> From: [email protected] [mailto:programming-
> [email protected]] On Behalf Of Roger Hui
> Sent: Thursday, January 28, 2010 2:41 AM
> To: Programming forum
> Subject: Re: [Jprogramming] Running Subtraction
> 
>    f=: 4 : 'c-~y*0=c=. 2-~/\0,x<.+/\y'
> 
>    a=: 2*5+i.5
>    35.5 f a
> _10 _12 _13.5 16 18
>    36 f a
> _10 _12 _14 16 18
> 
> It is possible that the application would be
> better served with the separate results
> 10 12 13.5 0 0 (used) and 0 0 0.5 16 18 (remainder)
> for 35.5 f a .
> 
> 
> 
> ----- Original Message -----
> From: Roger Hui <[email protected]>
> Date: Wednesday, January 27, 2010 8:59
> Subject: Re: [Jprogramming] Running Subtraction
> To: Programming forum <[email protected]>
> 
> > a*_1^0>:b-+/\a gets close, with a fix-up required
> > for the element on the boundary.
> > 
> > The result is the negation of the usage in each bin,
> > but unused bins retain their original values.
> > 
> > 
> > 
> > ----- Original Message -----
> > From: Raul Miller <[email protected]>
> > Date: Wednesday, January 27, 2010 8:45
> > Subject: Re: [Jprogramming] Running Subtraction
> > To: Programming forum <[email protected]>
> > 
> > > On Wed, Jan 27, 2010 at 10:54 AM, Alex Rufon 
> > <alex_ru...@ist-
> > > systems.com> wrote:
> > > >   [a=. 2 * 5 + i. 5
> > > > 10 12 14 16 18
> > > >   [b=. 35.5
> > > > 35.5
> > > ...
> > > > I want to subtract a from b progressively until b is 0 so 
> > from 
> > > the data above I'll get the following results:
> > > > _10 _12 _13.5 16 18
> > > 
> > > This description does not make sense to me.
> > > 
> > > Here are my guesses for where these numbers came from:
> > > 
> > > _10  -:  -0{a
> > > _12  -:  -1{a
> > > _13.5  -: b - +/0 1{a
> > > 16  -:  3{a
> > > 18  -:  4{a
> > > 
> > > But I can not figure out how my guesses relate to
> > > your description.
> > > 
> > > If I understood your description properly, you might
> > > be interested in something like:
> > >       b-+/\.&.|. a
> > > 25.5 13.5 _0.5 _16.5 _34.5
> > > or
> > >    0 >. b-+/\.&.|. a
> > > 25.5 13.5 0 0 0
> > > 
> > > But I am not at all confident that this is what you
> > > are looking for.
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