activpalProcessing (version 1.0.2)

sed.min.AP: Estimate Time in Sedentary

Description

This function to calculates the minutes spent sitting/lying.

Usage

sed.min.AP(posture, epoch = 1)

Arguments

posture

posture is a vector indicating sitting (0), standing (1) and stepping (2)

epoch

numeric value indicating what epoch (in seconds) the data are in (e.g. 60 = 1 minute epochs). The default value is 1 second

Value

a numeric value indicating minutes spent sedentary

Details

The default settings of the AP assign a met value of 1.25 to sitting, 1.4 to standing and estimates a met value for stepping activities. Cadence is used to estimate mets for stepping. With these settings all standing activity will be considered sedentary (e.g. < 1.5 mets). In the second-by-second function in this package standing met values are changed to 1.5 so that standing is considered a light intensity activity. Thus the only events considered sedentary are sitting/lying events

See Also

lit.min.AP mvpa.min.AP stand.min.AP step.min.AP

Examples

	
data(second.by.second.data)
posture <- second.by.second.data$ap.posture
	
sed.min.AP(posture,epoch=1)

# summarize by date
tapply(second.by.second.data$ap.posture, second.by.second.data$date, sed.min.AP,epoch=1)