RangeExtra version 10^-20 is officially out.  It consists of a small and
hopefully growing number of ranges that didn't make it into the new Phobos
that I've gotten working reasonably well and I feel eventually belong in Phobos.

Docs / What's there: http://cis.jhu.edu/~dsimcha/rangeextra.html

Code: http://dsource.org/projects/scrapple/browser/trunk/rangeextra/rangeextra.d

License:
Dual licensed, Phobos license or BSD (Tango style).

dsimcha wrote:

> RangeExtra version 10^-20 is officially out.  It consists of a small and
> hopefully growing number of ranges that didn't make it into the new Phobos
> that I've gotten working reasonably well and I feel eventually belong in Phobos.
>
> Docs / What's there:
> http://cis.jhu.edu/~dsimcha/rangeextra.html
>
> Code:
> http://dsource.org/projects/scrapple/browser/trunk/rangeextra/rangeextra.d
>
> License:
> Dual licensed, Phobos license or BSD (Tango style).

I had hoped reindex would give me access to true 'random' access ranges, but it seems this does not work:

 auto b = reindex!( "uniform( 0, this.length )" )( [0,1,2,3,4].dup );

:p

Simen Kjaeraas wrote:
> dsimcha wrote:
> 
>> RangeExtra version 10^-20 is officially out.  It consists of a small and
>> hopefully growing number of ranges that didn't make it into the new
>> Phobos
>> that I've gotten working reasonably well and I feel eventually belong
>> in Phobos.
>>
>> Docs / What's there: http://cis.jhu.edu/~dsimcha/rangeextra.html
>>
>> Code: http://dsource.org/projects/scrapple/browser/trunk/rangeextra/rangeextra.d
>>
>>
>> License:
>> Dual licensed, Phobos license or BSD (Tango style).
> 
> I had hoped reindex would give me access to true 'random' access ranges, but it seems this does not work:
> 
>  auto b = reindex!( "uniform( 0, this.length )" )( [0,1,2,3,4].dup );
> 
> :p

If I had to take a guess, I'd say it was because "uniform" isn't defined in the context of reindex.  Maybe this:

import std.random;

void foo()
{
    auto b = reindex!((i){ return uniform(0,5); })( [0,1,2,3,40.dup );
}

I don't think there's any way to get the length.

  -- Daniel

== Quote from Simen Kjaeraas (simen.kjaras@gmail.com)'s article
> dsimcha wrote:
> > RangeExtra version 10^-20 is officially out.  It consists of a small and
> > hopefully growing number of ranges that didn't make it into the new
> > Phobos
> > that I've gotten working reasonably well and I feel eventually belong in
> > Phobos.
> >
> > Docs / What's there: http://cis.jhu.edu/~dsimcha/rangeextra.html
> >
> > Code: http://dsource.org/projects/scrapple/browser/trunk/rangeextra/rangeextra.d
> >
> > License:
> > Dual licensed, Phobos license or BSD (Tango style).
> I had hoped reindex would give me access to true 'random' access ranges, but it
seems this does not work:
>   auto b = reindex!( "uniform( 0, this.length )" )( [0,1,2,3,4].dup );
> :p

Very cool idea.  Nothing like what I had in mind as a use case for Reindex, but half the fun of generic programming is seeing stuff get used for things you hadn't anticipated.

I spent some time trying, and for some reason I can't for the life of me get this example to work, or even the one where the length is hard-coded.  It may be some obscure compiler bug, because I'm just getting weird inscrutable error messages and I can't really figure out where they're coming from.

On the other hand, I really like the idea of a with-replacement random sampling primitive.  This sounds like it belongs in RandomCover.  Maybe Andrei can extend RandomCover (which already samples w/o replacement) to include a replacement parameter.  RandomCover w/ replacement == false would do what it does now.  If replacement == true, it would be an infinite range that samples with replacement.

== Quote from dsimcha (dsimcha@yahoo.com)'s article
> == Quote from Simen Kjaeraas (simen.kjaras@gmail.com)'s article
> > dsimcha wrote:
> > > RangeExtra version 10^-20 is officially out.  It consists of a small and
> > > hopefully growing number of ranges that didn't make it into the new
> > > Phobos
> > > that I've gotten working reasonably well and I feel eventually belong in
> > > Phobos.
> > >
> > > Docs / What's there: http://cis.jhu.edu/~dsimcha/rangeextra.html
> > >
> > > Code: http://dsource.org/projects/scrapple/browser/trunk/rangeextra/rangeextra.d
> > >
> > > License:
> > > Dual licensed, Phobos license or BSD (Tango style).
> > I had hoped reindex would give me access to true 'random' access ranges, but it
> seems this does not work:
> >   auto b = reindex!( "uniform( 0, this.length )" )( [0,1,2,3,4].dup );
> > :p

> On the other hand, I really like the idea of a with-replacement random sampling primitive.  This sounds like it belongs in RandomCover.  Maybe Andrei can extend RandomCover (which already samples w/o replacement) to include a replacement parameter.  RandomCover w/ replacement == false would do what it does now.  If replacement == true, it would be an infinite range that samples with replacement.

Here's a first attempt:  I took Andrei's RandomCover, fixed bug 2865 (This version of RandomCover passes basic statistical tests for uniformity of the distribution over the permutation space), and added a template overload to allow sampling with replacement.  It's under the Phobos license to make it as easy as possible to add back to Phobos.  I'll file an enhancement request.

http://dsource.org/projects/scrapple/browser/trunk/rangeextra/randomcover.d

在 Sat, 25 Apr 2009 23:40:03 +0800，dsimcha <dsimcha@yahoo.com> 写道:

> == Quote from dsimcha (dsimcha@yahoo.com)'s article
>> == Quote from Simen Kjaeraas (simen.kjaras@gmail.com)'s article
>> > dsimcha wrote:
>> > > RangeExtra version 10^-20 is officially out.  It consists of a  
>> small and
>> > > hopefully growing number of ranges that didn't make it into the new
>> > > Phobos
>> > > that I've gotten working reasonably well and I feel eventually  
>> belong in
>> > > Phobos.
>> > >
>> > > Docs / What's there:
>> > > http://cis.jhu.edu/~dsimcha/rangeextra.html
>> > >
>> > > Code:
>> > >  
>> http://dsource.org/projects/scrapple/browser/trunk/rangeextra/rangeextra.d
>> > >
>> > > License:
>> > > Dual licensed, Phobos license or BSD (Tango style).
>> > I had hoped reindex would give me access to true 'random' access  
>> ranges, but it
>> seems this does not work:
>> >   auto b = reindex!( "uniform( 0, this.length )" )( [0,1,2,3,4].dup );
>> > :p
>
>> On the other hand, I really like the idea of a with-replacement random sampling
>> primitive.  This sounds like it belongs in RandomCover.  Maybe Andrei can extend
>> RandomCover (which already samples w/o replacement) to include a replacement
>> parameter.  RandomCover w/ replacement == false would do what it does now.  If
>> replacement == true, it would be an infinite range that samples with replacement.
>
> Here's a first attempt:  I took Andrei's RandomCover, fixed bug 2865 (This version
> of RandomCover passes basic statistical tests for uniformity of the distribution
> over the permutation space), and added a template overload to allow sampling with
> replacement.  It's under the Phobos license to make it as easy as possible to add
> back to Phobos.  I'll file an enhancement request.
>
> http://dsource.org/projects/scrapple/browser/trunk/rangeextra/randomcover.d

Looking forward to it!

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