[Jprogramming] a new question

[Ric Sherlock]

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 <mikelpater at hotmail.es> 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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