Hi everyone,
thx for your solution. The question was wheter tacit programing is
supported in K or not.
That means is there a solution in K based purely on tacit programming
(argument free) for the mean problem without using explicitly the lambda
formulation?
Regards,
Kim
Am 17.01.2012 00:55, schrieb Mike Day:
> Apologies - this probably should be in jchat.
>
> In KDB (Q), you can revert to K with \
>
> Then you can calculate a mean in similar fashion to
> APL or J. The symbols for the primitives are slightly
> different but very like in execution,
>
> K's ! ~ J's i. ~ APL's iota .
> K's # ~ J's # ~ APL's rho .
>
> Here are three lines from a kdb session:
>
> q)\ / escape to K from Q
> {(+/x)%#x}[!10] / mean
> 4.5
>
> K's functions are a bit like Dyalog APL's dynamic
> functions, J's explicit functions or Pari-GP's
> user-defined functions.
>
> til and count are Q cover functions for K's ! and # .
> eg the file q.k contains this definition:
>
> til:{$[-6h=@x;!x;'`type]}
>
> The fine details escape me, but you can see ! x
> in there!
>
> Mike
>
> PS - median is not the same as mean.
>
> On 16/01/2012 8:31 PM, mikel paternain wrote:
>> Here a first aproximation.
>>
>> - define a list(unidimensional vector) For example the firs ten integer
>> numbers. q) is the prompt in Q system.
>> q) L: 1 2 3 4 5 6 7 8 9 10
>>
>> - next, sum all integers
>> q) suminteger: sum L
>>
>> - now, count elements of L
>> number: count L
>>
>> -and to end, compute the mean
>> q) median: suminteger%number
>>
>> Another way is
>>
>> q) (sum L)%(count L)
>> 5.5
>>
>> In Q the function to obtain integers is til
>>
>> q) til 10
>> 0 1 2 3 4 5 6 7 8 9
>>
>> Best,
>>
>> Mikel
>>
>>
>>>> Message: 1
>>> Date: Mon, 16 Jan 2012 17:11:09 +0100
>>> From: Kim Kuen Tang<kuent...@vodafone.de>
>>> Subject: Re: [Jprogramming] Advantages of J over Q (aka K4/Kdb+)
>>> To: Programming forum<programming@jsoftware.com>
>>> Message-ID:<4f144c1d.90...@vodafone.de>
>>> Content-Type: text/plain; charset=UTF-8; format=flowed
>>>
>>>
>>> I tried to calculate the mean in K using tacit programming.
>>> (+/%# ) !10
>>> But it is not working. Can you show how to program it in K?
>>>
>>
>> ----------------------------------------------------------------------
>> For information about J forums seehttp://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
