Sorry, it should be

$shuffled = $data(qsorti(random($data)))


Marek

On Thu, 6 Aug 2015 at 18:11 Marek Gierliński <[email protected]>
wrote:

> I normally do it this way
>
> $shuffled = $data(qsorti(random($x)))
>
> Marek
>
> On Thu, 6 Aug 2015 at 18:06 David Mertens <[email protected]>
> wrote:
>
>> Hey Nick,
>>
>> I'm not sure how fast this is, but this is what I do when I need to
>> randomly sort things:
>>
>> # Assuming you have $data already declared...
>> $shuffled = cat($data->random, $data)->transpose->qsortvec->(1)->flat
>>
>> The call "->(1)" is a NiceSliceism; replace with a slice method call if
>> that's not on.
>>
>> Bear in mind that PDL's random number generator is Perl's default, which
>> is not sufficiently random for most Monte Carlo stuff. I've never needed
>> anything more sophisticated for my work, but I suspect that the PDL
>> bindings to GSL provide random generators of higher quality.
>>
>> Good luck!
>> David
>>
>> On Thu, Aug 6, 2015 at 12:59 PM, Nick Wright <[email protected]>
>> wrote:
>>
>>> Hi everyone
>>>
>>> I need help with something that I think *should* be simple with Perl/PDL
>>> but I can't find the command for it.
>>>
>>> I basically just want to randomly re-order a 1-dimensional, moderately
>>> long (1500 entries) piddle and I can't find a simple way. I need to do this
>>> for the purposes of a Monte Carlo simulation, so I was hoping PDL might
>>> have an efficient way to do it so I can repeat is 1000s of times quickly!
>>>
>>> Thanks in advance for the help!
>>>
>>> Cheers,
>>>
>>> Nick
>>>
>>>
>>> ------------------------------------------------------------------------------
>>>
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>>> [email protected]
>>> https://lists.sourceforge.net/lists/listinfo/pdl-general
>>>
>>>
>>
>>
>> --
>>  "Debugging is twice as hard as writing the code in the first place.
>>   Therefore, if you write the code as cleverly as possible, you are,
>>   by definition, not smart enough to debug it." -- Brian Kernighan
>>
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>>
> --
> Dr Marek Gierliński
> The Data Analysis Group
> The Barton Group
> Computational Biology and GRE
> School of Life Sciences
> University of Dundee, Dundee, Scotland, UK.
> Tel: +44 1382 386427
> www.compbio.dundee.ac.uk/dag.html
>
-- 
Dr Marek Gierliński
The Data Analysis Group
The Barton Group
Computational Biology and GRE
School of Life Sciences
University of Dundee, Dundee, Scotland, UK.
Tel: +44 1382 386427
www.compbio.dundee.ac.uk/dag.html
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