Sigma0 {ActivityIndex} | R Documentation |
Sigma0
computes \bar{σ}_i, which is needed for
the Activity Index computing in computeActivityIndex
Sigma0(x, hertz = 30)
x |
A 4-column data frame containing the raw accelerometry data when the device is not worn. The 1st column has the record/index number. The 2nd to 4th columns contain the tri-axial raw acceleration. The data will be used to calculate \bar{σ}_i. |
hertz |
The sample rate of the data. |
\bar{σ}_i, a numeric vector of length one.
filename = system.file("extdata","sample_GT3X+.csv.gz",package="ActivityIndex") res = ReadGT3XPlus(filename) hertz = res$Hertz x = res$Raw[ 1:1000, c("Time", "X", "Y", "Z")] res = Sigma0(x, hertz = hertz) testthat::expect_equal(res, c(SD = 0.184321637135534))