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Shift Data Range

Source: R/shift_data.R
shift_data.Rd

Move the range of data channels in a dataframe up or down, while preserving the absolute dynamic range and/or relative scaling across channels. e.g. shift data range to positive values, or shift the first value of a recording to zero.

Usage

shift_data(
  data,
  nirs_columns = list(),
  shift_to = 0,
  position = c("minimum", "maximum", "first"),
  mean_samples = 1,
  shift_by = NULL
)

Arguments

data

A dataframe.

nirs_columns

A list() of character vectors indicating the column names for data channels to be shifted (see Details).

shift_to

A numeric scalar to which the specified data channels will be shifted to.

position

Indicates how to shift values.

"minimum"

will shift selected channels' minimum values to the specified shift_to value (default).

"maximum"

will shift selected channels by their maximum values.

"first"

will shift selected channels by their first values.

mean_samples

An integer scalar representing the number of samples over which the position is determined. e.g., mean_samples = 1 looks for the single minimum, maximum, or first value. mean_samples = 30 would use the mean of the lowest, highest, or first 30 samples.

shift_by

An optional numeric scalar by which the data signals can be shifted by a set amount.

Value

A tibble of class mNIRS.data with metadata available with attributes().

Details

nirs_columns = list() can be used to group data columns to preserve absolute or relative scaling. channels grouped together in a vector will preserve relative scaling across channels. Should match column names in the dataframe exactly.

nirs_columns = list("A", "B", "C")

will shift each column separately. Absolute dynamic range for each data channel is preserved, but relative scaling will be lost between data channels.

nirs_columns = list(c("A", "B", "C"))

will shift all columns together. Absolute dynamic range and relative scaling are both preserved across the group of data channels.

nirs_columns = list(c("A", "B"), c("C", "D"))

will shift columns A and B together, and columns C and D together. Absolute dynamic range and relative scaling are preserved within each group, but not across groups of data channels.