Collapse Accelerometer Data to a Dataset with a Longer Epoch
Collapse Accelerometer Data to a Dataset with a Longer Epoch
The function collapses counts in data collected with a short epoch to make a data set with a longer epoch. For example, this function collapses data with 1-sec epoch to 10-sec epoch or 1-min epoch data.
dataset: The source dataset, in dataframe format, that needs to be collapsed.
TS: The column name for timestamp.
by: Epoch in seconds for a collapsed dataset. For example, to collapse second data to minute data, set by = 60; to collapse 10-second data to minute data, set by = 60.
col: The column name(s) to collapse. If not provided, will default to all numeric columns.
func: A method for collapsing counts. The default is the summation of counts.
...: Argument settings that to be used by user-defined "func" setting.
Returns
A collapsed data with user specified epoch.
Examples
data(dataSec)## collapse 1-sec epoch data to 10-sec epoch datamydata10s = dataCollapser(dataSec, TS ="TimeStamp", col ="counts", by =10)## collapse 1-sec epoch data to 1-min epoch datamydata1m = dataCollapser(dataSec, TS ="TimeStamp", col ="counts", by =60)
References
Choi L, Liu Z, Matthews CE, Buchowski MS. Validation of accelerometer wear and nonwear time classification algorithm. Med Sci Sports Exerc. 2011 Feb;43(2):357-64.