With infinite rank:
tent =: -:@:(|&.(0.5&-))
tent _0.1 0 0.1 0.2 0.3 0.5 0.7 0.8 0.9 1 1.1
_0.05 0 0.05 0.1 0.15 0.25 0.15 0.1 0.05 0 _0.05
I got nothin' on the infinite sum (which looks to me like it has a typo
in the spec)
Henry Rich
On 8/28/2011 10:38 AM, Marshall Lochbaum wrote:
> How about
>
> tent=: 0>. [:-: -.^:(>&0.5)"0
> tent _0.1 0 0.1 0.2 0.3 0.5 0.7 0.8 0.9 1 1.1
> 0 0 0.05 0.1 0.15 0.25 0.15 0.1 0.05 0 0
>
> Marshall
>
> On Sun, Aug 28, 2011 at 7:47 AM, Ric Sherlock<[email protected]> wrote:
>
>> Here's one tacit approach to the tent function:
>> tent=: 0:`-:`(-:@-.)`0:@.(0 0.5 1&I.)"0
>> tent _0.1 0 0.1 0.2 0.3 0.5 0.7 0.8 0.9 1 1.1
>> 0 0 0.05 0.1 0.15 0.25 0.15 0.1 0.05 0 0
>>
>> Given it is rank 0 I expect its performance can be improved. Also
>> although dyadic I. appears to work in this case, it doesn't strictly
>> follow the 0<=x condition below.
>>
>> On Sun, Aug 28, 2011 at 10:40 PM, mikel paternain<[email protected]>
>> wrote:
>>>
>>> How do you write in J a "tent" function:
>>>
>>> g(x)= x/2 if 0<=x<=1/2,
>>> (1-x)/2 if 1/2< x< 1
>>>
>>> and, more important, How do you write in J a Takagi function with the
>> "tent" function:
>>>
>>> h(x)= Sum [r=0 to infinite, g(2^r x)/2^r]
>>>
>>>
>>>
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>>>
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>>
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