atl_remove_reflections: Remove reflected positions.

In pratikunterwegs/atlastools: Tools for Pre-Processing High-Throughput Animal Tracking Data

Description

Remove reflections, or prolonged spikes from a movement track by identifying the bounds and removing positions between them. The important function arguments here are point_angle_cutoff ($A$), reflection_speed_cutoff ($S$). If the prolonged spike ends before the last row of data, the true end point is used as the outer bound of the spike. If the prolonged spike does not end within the last row of data, all the data are retained and a message is printed.

Usage

atl_remove_reflections(
  data,
  x = "x",
  y = "y",
  time = "time",
  point_angle_cutoff = 45,
  reflection_speed_cutoff = 20
)

Arguments

data	A dataframe or similar which has previously been cleaned.
x	The name of the X coordinate column.
y	The name of the Y coordinate column.
time	The name of the timestamp column.
point_angle_cutoff	The turning angle (in degrees) above which high instantaneous speeds are considered an anomaly rather than fast transit.
reflection_speed_cutoff	The speed (in m/s) above which an anomaly is detected when combined with a high turning angle.

Value

A dataframe with reflections removed.

Author(s)

Pratik R. Gupte

Examples

## Not run: 
filtered_data <- atl_remove_reflections(
  data = track_data,
  x = "x", y = "y", time = "time",
  point_angle_cutoff = A,
  reflection_speed_cutoff = S
)

## End(Not run)

pratikunterwegs/atlastools documentation built on Nov. 7, 2021, 7:14 p.m.