Re: [racket-dev] Feature request: Vector-sort

2012-07-29 Thread Eli Barzilay 
7 hours ago, Harry Spier wrote:
> On Sun, Jul 29, 2012 at 6:12 PM, Eli Barzilay  wrote:
> 
> > Actually, the `sort' code uses a vector to do its work, which is
> > initialized from the input list.  But it doesn't help much to make it
> > deal with vectors too, since the vector that is used for the sorting
> > work needs to be bigger than the input -- so to sort a vector you'd
> > still need to create a copy.  Given that, you can usually just do the
> > usual (list->vector (sort (vector->list v) <)).
> 
> Thanks Eli.  Thats in fact what I'm presently doing.  i.e. vector->list
> 
> Its on a vector of 26000 structs each consisting of 4 numbers and two
> very short lists of numbers (0-2 or 3 numbers each).

Then you only have the 26000 values to copy -- the contents of the
vector is still the same in the list copy.

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Re: [racket-dev] Feature request: Vector-sort

2012-07-29 Thread Harry Spier 
On Sun, Jul 29, 2012 at 6:12 PM, Eli Barzilay  wrote:

> Actually, the `sort' code uses a vector to do its work, which is
> initialized from the input list.  But it doesn't help much to make it
> deal with vectors too, since the vector that is used for the sorting
> work needs to be bigger than the input -- so to sort a vector you'd
> still need to create a copy.  Given that, you can usually just do the
> usual (list->vector (sort (vector->list v) <)).

Thanks Eli.  Thats in fact what I'm presently doing.  i.e. vector->list

Its on a vector of 26000 structs each consisting of 4 numbers and two
very short lists of numbers (0-2 or 3 numbers each).

Harry
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Re: [racket-dev] Feature request: Vector-sort

2012-07-29 Thread Pierpaolo Bernardi 
Also:

(require data/heap)

heap-sort!



2012/7/30, Eli Barzilay :
> A few minutes ago, Harry Spier wrote:
>> I would find a sort function for vectors very useful.
>
> Actually, the `sort' code uses a vector to do its work, which is
> initialized from the input list.  But it doesn't help much to make it
> deal with vectors too, since the vector that is used for the sorting
> work needs to be bigger than the input -- so to sort a vector you'd
> still need to create a copy.  Given that, you can usually just do the
> usual (list->vector (sort (vector->list v) <)).
>
> --
>   ((lambda (x) (x x)) (lambda (x) (x x)))  Eli Barzilay:
> http://barzilay.org/   Maze is Life!
> _
>   Racket Developers list:
>   http://lists.racket-lang.org/dev
>

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Re: [racket-dev] Feature request: Vector-sort

2012-07-29 Thread Eli Barzilay 
A few minutes ago, Harry Spier wrote:
> I would find a sort function for vectors very useful.

Actually, the `sort' code uses a vector to do its work, which is
initialized from the input list.  But it doesn't help much to make it
deal with vectors too, since the vector that is used for the sorting
work needs to be bigger than the input -- so to sort a vector you'd
still need to create a copy.  Given that, you can usually just do the
usual (list->vector (sort (vector->list v) <)).

-- 
  ((lambda (x) (x x)) (lambda (x) (x x)))  Eli Barzilay:
http://barzilay.org/   Maze is Life!
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  http://lists.racket-lang.org/dev

[racket-dev] Feature request: Vector-sort

2012-07-29 Thread Harry Spier 
I would find a sort function for vectors very useful.

Thanks,
Harry Spier
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