Jessica wrote:
> 1. Average sample rate is in the ms range, but can vary to seconds /
> minutes when there is no activity to be measured.
> 2. Most of the sample intervals are in the ms range, but accuracy down
> to the microsecond is possible. However, at that level, mostly noise
> is recorded. I want to downsample to one measurement per second or
> even minute.
> 3. I am not sure how to quantify this, the signal measured does
> contain a lot of noise, but ideally, I would like to use a Hull Moving
> Average to smooth the data.
>
> I appreciate your help.
>
> On Feb 1, 5:29 pm, Richard Owlett <rowl...@pcnetinc.com> wrote:
>> Jessica wrote:
>>> I am looking for an open-source smoother to down-sample data. I know
>>> there are many such as Hull Moving average, but I have data logged at
>>> the ms scale at non-fixed time intervals and I want to sample it on
>>> the second range at fixed time intervals. Does anyone know of a good
>>> smoother to do this? The key is that the input data is not logged at a
>>> constant frequency.
>> Can't answer your specific question. *BUT* I can suggest
>> information to give so you can get a meaningful answer:
>>
>> 1. What is the average sample rate?
>> 2. What is the minimum and maximum time between samples?
>> 2a. Possibly, what is the distribution of sample intervals?
>> 3. What is your desired fixed "sample rate"?
>> 4. What accuracy constraints of fit of reconstructed signal to
>> the actual? [Would linear interpolation between points be
>> adequate or would a 310947 degree polynomial be needed?
>> [Alright already, the degree was tongue in cheek, but intent
>> was serious.]
>>
>> The art of getting "right answer" is asking "right question" ;>
>> [I *KNOW* from personal embarrassing experience.]
Another question: How does the sampling rate compare to the bandwidth of
your data?

Jerry
--
Engineering is the art of making what you want from things you can get.
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