I'm not sure. May be I should use memoization instead. I have a bunch of
recursive functions f,g,h,... defined like this:
F(t,i,j,k) is a minimum of
{C(i,j,k)+ sum of all g(t-1, i',j',k) + sum of all h(t-1, i, j", k') }
and
{F(t,i-1,j,k-1)+1},
where C -- user defined cost function,
i' from 0 to i-1, j' and j" from zero to j-1, k' from 0 to k-j.
I'm intrested in a value of F(T,N,M,K) for some T,N,M,K ≤ 1000. A common
pattern for tasks like this would be very helpful for me.
04 апр. 2015 г. 23:50 пользователь "Henry Rich" <[email protected]>
написал:
> It's unusual in J to need the full odometer array. Are you sure that your
> problem requires it?
>
> Henry rich
>
> On 4/4/2015 5:48 PM, Sergeif wrote:
>
>> Thanks! It's 10x faster than my code but 10x slower than odometer
>> function.
>> Anyway I lernt the catalogue verb from this.
>>
>> On Sat, Apr 4, 2015 at 11:21 PM, R.E. Boss <[email protected]> wrote:
>>
>>
>>> >,{<@i."0[2 3 4
>>> 0 0 0
>>> 0 0 1
>>> 0 0 2
>>> 0 0 3
>>> 0 1 0
>>> 0 1 1
>>> 0 1 2
>>> 0 1 3
>>> 0 2 0
>>> 0 2 1
>>> 0 2 2
>>> 0 2 3
>>> 1 0 0
>>> 1 0 1
>>> 1 0 2
>>> 1 0 3
>>> 1 1 0
>>> 1 1 1
>>> 1 1 2
>>> 1 1 3
>>> 1 2 0
>>> 1 2 1
>>> 1 2 2
>>> 1 2 3
>>>
>>> R.E. Boss
>>>
>>>
>>> -----Original Message-----
>>>> From: [email protected] [mailto:programming-
>>>> [email protected]] On Behalf Of Nollaig MacKenzie
>>>> Sent: zaterdag 4 april 2015 23:16
>>>> To: [email protected]
>>>> Subject: Re: [Jprogramming] indexing a table
>>>>
>>>> Is something like this what you have in mind?
>>>>
>>>> m=. i. 2 3 4
>>>> indmak m
>>>> 0 0 0
>>>> 0 0 1
>>>> 0 0 2
>>>> 0 0 3
>>>>
>>>> 0 1 0
>>>> 0 1 1
>>>> 0 1 2
>>>> 0 1 3
>>>>
>>>> 0 2 0
>>>> 0 2 1
>>>> 0 2 2
>>>> 0 2 3
>>>>
>>>>
>>>> 1 0 0
>>>> 1 0 1
>>>> 1 0 2
>>>> 1 0 3
>>>>
>>>> 1 1 0
>>>> 1 1 1
>>>> 1 1 2
>>>> 1 1 3
>>>>
>>>> 1 2 0
>>>> 1 2 1
>>>> 1 2 2
>>>> 1 2 3
>>>> indmak
>>>> (#: i.)@$
>>>>
>>>>
>>>> On 2015.04.04 23:09:58, you,
>>>> the extraordinary Sergeif, spake thus:
>>>>
>>>> Hi.
>>>>>
>>>>> How can someone create list of indexes of 3d table (N x M x K)?
>>>>>
>>>>> I have written this simple code:
>>>>>
>>>>> ind3d =: 3 : 0
>>>>> 'n m k' =. y
>>>>> p0 =. k&|
>>>>> p1 =. (m&|)@:<.@:(%&k)
>>>>> p2 =. <.@:(%&(m*k))
>>>>> (p2 , p1 , p0)"0 (i. (n*m*k))
>>>>> )
>>>>>
>>>>> but it's very very slow. Does any tacit solution for this problem
>>>>>
>>>> exist?
>>>
>>>>
>>>>> Another question is how to fill the table with values depending on
>>>>>
>>>> indexes
>>>
>>>> of cell? For example, F[i,j,k] = (i * j) - (i * k) + (j * k).
>>>>> ----------------------------------------------------------------------
>>>>> For information about J forums see
>>>>>
>>>> http://www.jsoftware.com/forums.htm
>>>>
>>>> --
>>>> Nollaig MacKenzie
>>>> http://www.yorku.ca/nollaig
>>>> ----------------------------------------------------------------------
>>>> For information about J forums see http://www.jsoftware.com/forums.htm
>>>>
>>> ----------------------------------------------------------------------
>>> For information about J forums see http://www.jsoftware.com/forums.htm
>>>
>>> ----------------------------------------------------------------------
>> For information about J forums see http://www.jsoftware.com/forums.htm
>>
>> ----------------------------------------------------------------------
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>
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