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Create calibration functions for raw acceleration values

Source: R/acc_calibrate.R
acc_calibration.Rd

Generate an acc_calibration object containing a list of functions with various calibration parameters to be used in acc_calibrate().

Use acc_calibration() to specify calibration parameters manually. Arguments are vectorized and matched by index.

Use as_acc_calibration() to convert a data.frame containing row-wise burst calibration parameters to an acc_calibration object.

This allows you to specify burst-specific calibration functions to flexibly convert raw acceleration values to physical units in acc vectors that contain data from heterogeneous sources.

Usage

acc_calibration(
  manufacturer = NULL,
  tag_id = NULL,
  sensitivity = NULL,
  offset = NULL,
  offset_x = offset,
  offset_y = offset,
  offset_z = offset,
  slope = NULL,
  slope_x = slope,
  slope_y = slope,
  slope_z = slope,
  orientation = NULL,
  orientation_x = orientation,
  orientation_y = orientation,
  orientation_z = orientation,
  units = "m/s^2",
  axes = "XYZ"
)

as_acc_calibration(df)

Arguments

manufacturer

Manufacturer of the tag. Currently, "eobs" and "ornitela" are supported. For other manufacturers, leave NULL and manually specify the calibration parameters below.

tag_id

If manufacturer = "eobs", the e-obs tag ID for the tag.

sensitivity

If manufacturer = "eobs", the sensitivity of the tag. Defaults to "low" if none provided. Note that only e-obs generation 1 tags have a sensitivity setting.

offset, offset_x, offset_y, offset_z

Custom offset to use when calibrating. To specify axis-specific offsets, use offset_x, offset_y, and/or offset_z.

Required if no manufacturer is specified.

slope, slope_x, slope_y, slope_z

Custom slope to use when calibrating. To specify axis-specific slope, use slope_x, slope_y, and/or slope_z.

Required if no manufacturer is specified.

orientation, orientation_x, orientation_y, orientation_z

Either 1 or -1 indicating the orientation of the tag's axes. To specify axis-specific orientations, use orientation_x, orientation_y, and/or orientation_z. Defaults to 1.

This is useful to standardize orientations across tags of different manufacturers or generations.

units

Output units. Either "m/s^2" (default) or "standard_free_fall".

axes

Character string specifying which axes to calibrate, e.g., "XYZ" (default), "XY", or "Z". Only these axes will appear in the calibrated output.

df

data.frame containing columns corresponding to the available arguments in acc_calibration()

Value

An acc_calibration object.

See also

acc_calibrate() to apply calibration functions to the entries in an acc vector.

Examples

# Calibration for ornitela tags:
acc_calibration(manufacturer = "ornitela")
#> <acc_calibration[1]>

# E-obs tag defaults vary by tag_id and sensitivity (default `"low"`)
acc_calibration(manufacturer = "eobs", tag_id = 1000, sensitivity = "high")
#> <acc_calibration[1]>
acc_calibration(manufacturer = "eobs", tag_id = 4000)
#> <acc_calibration[1]>

# Provide vector arguments to generate element-wise calibrations:
acc_calibration(
  manufacturer = c("eobs", "ornitela"),
  tag_id = c(1000, NA)
)
#> <acc_calibration[2]>

# Calibration with explicit offset and slope
acc_calibration(offset = 2048, slope = 1 / 512)
#> <acc_calibration[1]>

# Calibrate specific axes with axis-specific args:
cal <- acc_calibration(
  offset_x = 2048, 
  offset_y = 2046,
  offset_z = 2048,
  slope = 1 / 512, 
  orientation_y = -1 # Flip y axis orientation
)

# Apply calibration with acc_calibrate()
acc_calibrate(acc_example(), cal)
#> <acceleration[2]>
#> [1] (-39.21 39.19 -39.21) [m/s^2] (-39.23 39.2 -39.21) [m/s^2] 
#> # frequency: 20 [Hz]