Looking at a stream of values from a phone's accelerometer,
I can see that they jitter about quite a bit.  If I were to
control some aspect of a sound, pitch for instance, I would
expect the result to sound the same way - rather erratic.

What is the usual way to 'dampen' those values so that they
follow a smooth curve?  I'd expect to trade off
responsiveness for smoothness.  I actually need the
algorithm (computer code really) rather than a reference to
a csound opcode.  I suppose it has to do with collecting
and averaging the values ahead of time, but I thought I'd
ask about it since there must have been a lot of work done
on this sort of thing.


Thanks!


Tobiah

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Lowpass filtering does not do the job?

Victor Lazzarini
Dean of Arts, Celtic Studies, and Philosophy
Maynooth University
Ireland

> On 6 Mar 2016, at 16:24, Tobiah  wrote:
> 
> Looking at a stream of values from a phone's accelerometer,
> I can see that they jitter about quite a bit.  If I were to
> control some aspect of a sound, pitch for instance, I would
> expect the result to sound the same way - rather erratic.
> 
> What is the usual way to 'dampen' those values so that they
> follow a smooth curve?  I'd expect to trade off
> responsiveness for smoothness.  I actually need the
> algorithm (computer code really) rather than a reference to
> a csound opcode.  I suppose it has to do with collecting
> and averaging the values ahead of time, but I thought I'd
> ask about it since there must have been a lot of work done
> on this sort of thing.
> 
> 
> Thanks!
> 
> 
> Tobiah
> 
> Csound mailing list
> Csound@listserv.heanet.ie
> https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
> Send bugs reports to
>       https://github.com/csound/csound/issues
> Discussions of bugs and features can be posted here

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It would, I'm sure.  I was hoping for a bit
of code I could put in my program.  At least
I have a better term to Google now!

Thanks,

Tobiah

On 3/6/2016 8:58 AM, Victor Lazzarini wrote:
> Lowpass filtering does not do the job?
>
> Victor Lazzarini
> Dean of Arts, Celtic Studies, and Philosophy
> Maynooth University
> Ireland
>
>> On 6 Mar 2016, at 16:24, Tobiah  wrote:
>>
>> Looking at a stream of values from a phone's accelerometer,
>> I can see that they jitter about quite a bit.  If I were to
>> control some aspect of a sound, pitch for instance, I would
>> expect the result to sound the same way - rather erratic.
>>
>> What is the usual way to 'dampen' those values so that they
>> follow a smooth curve?  I'd expect to trade off
>> responsiveness for smoothness.  I actually need the
>> algorithm (computer code really) rather than a reference to
>> a csound opcode.  I suppose it has to do with collecting
>> and averaging the values ahead of time, but I thought I'd
>> ask about it since there must have been a lot of work done
>> on this sort of thing.
>>
>>
>> Thanks!
>>
>>
>> Tobiah
>>
>> Csound mailing list
>> Csound@listserv.heanet.ie
>> https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
>> Send bugs reports to
>>        https://github.com/csound/csound/issues
>> Discussions of bugs and features can be posted here
>
> Csound mailing list
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> Send bugs reports to
>          https://github.com/csound/csound/issues
> Discussions of bugs and features can be posted here
>

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You might want to look at the port opcode's source:

https://github.com/csound/csound/blob/develop/OOps/ugens5.c

The first two functions, porset() and port(), are the code.  It's
essentially the same as a lowpass filter:

https://ccrma.stanford.edu/~jos/filters/Definition_Simplest_Low_Pass.html

If you step through the code mentally, it should make sense how it
smooths out values over time.

On Sun, Mar 6, 2016 at 12:26 PM, Tobiah  wrote:
> It would, I'm sure.  I was hoping for a bit
> of code I could put in my program.  At least
> I have a better term to Google now!
>
> Thanks,
>
> Tobiah
>
>
> On 3/6/2016 8:58 AM, Victor Lazzarini wrote:
>>
>> Lowpass filtering does not do the job?
>>
>> Victor Lazzarini
>> Dean of Arts, Celtic Studies, and Philosophy
>> Maynooth University
>> Ireland
>>
>>> On 6 Mar 2016, at 16:24, Tobiah  wrote:
>>>
>>> Looking at a stream of values from a phone's accelerometer,
>>> I can see that they jitter about quite a bit.  If I were to
>>> control some aspect of a sound, pitch for instance, I would
>>> expect the result to sound the same way - rather erratic.
>>>
>>> What is the usual way to 'dampen' those values so that they
>>> follow a smooth curve?  I'd expect to trade off
>>> responsiveness for smoothness.  I actually need the
>>> algorithm (computer code really) rather than a reference to
>>> a csound opcode.  I suppose it has to do with collecting
>>> and averaging the values ahead of time, but I thought I'd
>>> ask about it since there must have been a lot of work done
>>> on this sort of thing.
>>>
>>>
>>> Thanks!
>>>
>>>
>>> Tobiah
>>>
>>> Csound mailing list
>>> Csound@listserv.heanet.ie
>>> https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
>>> Send bugs reports to
>>>        https://github.com/csound/csound/issues
>>> Discussions of bugs and features can be posted here
>>
>>
>> Csound mailing list
>> Csound@listserv.heanet.ie
>> https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
>> Send bugs reports to
>>          https://github.com/csound/csound/issues
>> Discussions of bugs and features can be posted here
>>
>
> Csound mailing list
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Smoothing can be done with port or tone, which are effectively the same filter but with
different means of controlling the amount of 
smoothing.

Victor Lazzarini
Dean of Arts, Celtic Studies, and Philosophy
Maynooth University
Ireland

> On 6 Mar 2016, at 17:26, Tobiah  wrote:
> 
> It would, I'm sure.  I was hoping for a bit
> of code I could put in my program.  At least
> I have a better term to Google now!
> 
> Thanks,
> 
> Tobiah
> 
>> On 3/6/2016 8:58 AM, Victor Lazzarini wrote:
>> Lowpass filtering does not do the job?
>> 
>> Victor Lazzarini
>> Dean of Arts, Celtic Studies, and Philosophy
>> Maynooth University
>> Ireland
>> 
>>> On 6 Mar 2016, at 16:24, Tobiah  wrote:
>>> 
>>> Looking at a stream of values from a phone's accelerometer,
>>> I can see that they jitter about quite a bit.  If I were to
>>> control some aspect of a sound, pitch for instance, I would
>>> expect the result to sound the same way - rather erratic.
>>> 
>>> What is the usual way to 'dampen' those values so that they
>>> follow a smooth curve?  I'd expect to trade off
>>> responsiveness for smoothness.  I actually need the
>>> algorithm (computer code really) rather than a reference to
>>> a csound opcode.  I suppose it has to do with collecting
>>> and averaging the values ahead of time, but I thought I'd
>>> ask about it since there must have been a lot of work done
>>> on this sort of thing.
>>> 
>>> 
>>> Thanks!
>>> 
>>> 
>>> Tobiah
>>> 
>>> Csound mailing list
>>> Csound@listserv.heanet.ie
>>> https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
>>> Send bugs reports to
>>>       https://github.com/csound/csound/issues
>>> Discussions of bugs and features can be posted here
>> 
>> Csound mailing list
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>> Send bugs reports to
>>         https://github.com/csound/csound/issues
>> Discussions of bugs and features can be posted here
> 
> Csound mailing list
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> Send bugs reports to
>       https://github.com/csound/csound/issues
> Discussions of bugs and features can be posted here

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