Time series or Ordered series

[Fostel, Jennifer (NIH/NIEHS) [C]]

Chris asked a DENRIEr to start a thread on this topic and I volunteered.  the question is about Time series -- does this require time or is time an example; and if time series is a unique case, how to represent time.

 

From DENRIE:

term: time series collection

definition: a time series collection is a data collection that is a sequence of data points, measured typically at successive times, spaced at (often uniform) time intervals.

definition source: Wikipedia

examples: gene expression measurements of cells taken from a culture over a series of days.

restrictions:

         is_output_of some measurement

         is_input_to some data transformation original request from James:

 

> DT requires the concept of 'time series' which would serve as input  > to some  > of the DTs that deal with this. As a starting point for time series,  > here  > is the wikipedia def: "A time series is a sequence of data points,  > measured  > typically at successive times, spaced at (often uniform) time  > intervals".

 

Chris today thought that the actual times were not critical, but the order of data points was.  This would push the example to an ordered series.

 

If we need ordered series, then the definition would run something along these lines.....

an ordered series (syn sequence) is a dataset having elements secceeding in order according to a rule.

 

If we need specifically time series then time series would be a subclass of ordered series where the rule specifies the time of collection of the specimen or data.

 

Alan and I think that we should associate the time with the data, as in pairs of data {measurment of time instant, output of measurement}

or describe the time of collection of the specimen in the design or protocol document (collect specimens at 1-hour intervals over a day / specimens were collected one hour after the drug was injected) and associate the specimen and the design or protocol with the data.

 

we will discuss this at the next DENRIE meeting, so stay tuned or comment on this thread.

 

thanks!

 

...jennifer

 

 

 

 

Jennifer Fostel, Ph.D.

CEBS Scientific Administrator

Global Health Sector, SRA International, Inc

 

Laboratory of Respiratory Biology

NIEHS, NIH

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