[PD] pow/pow~ and negative input, a fix proposal

Martin Peach chakekatzil at gmail.com
Wed May 9 04:18:39 CEST 2018


On Tue, May 8, 2018 at 9:28 PM, Alexandre Torres Porres <porres at gmail.com>
wrote:

> 2018-05-08 18:05 GMT-03:00 Martin Peach <chakekatzil at gmail.com>:
>
>> On Tue, May 8, 2018 at 2:07 PM, Alexandre Torres Porres <porres at gmail.com
>> > wrote:
>>
>>> ...
>>> I personally cannot think of any use case where someone relies on
>>> pow(-1, 2) generating "0", it just seems wrong to me (i.e. a bug) and
>>> allowing it to do that wouldn't break things.
>>>
>>> Maybe add another outlet for the imaginary part?
>>
>
>  but simply  pow(-1, 2)  does not generate an imaginary part, right?
>
> Right, sorry I was thinking of pow(-1, 0.5). pow(-1,2) should give 1.
Useful if you wanted to make a parabolic waveform in a table or something
like that. And I think pow(-1, 0.5) should give a 'NaN' instead of 0 if
we're sticking to Real numbers. I'm not sure if something like [select NaN
Inf -Inf] works in Pd. It doesn't give any error on creation but how to
generate the input?
So ideally this:

[-1{
|
[pow 0.5]
|
[sel NaN]
|      |

would emit a bang from the left outlet.

Martin
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