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Filter values by speed threshold

Source: R/filter_na_speed.R
filter_na_speed.Rd

This function filters out values in a dataset where the calculated speed exceeds a specified threshold. Values for x, y, and confidence are replaced with NA if their corresponding speed exceeds the threshold. Speed is calculated using the calculate_kinematics function.

Usage

filter_na_speed(data, threshold = "auto")

Arguments

data

A data frame containing the following required columns:

  • x: x-coordinates

  • y: y-coordinates

  • time: time values Optional column:

  • confidence: confidence values for each observation

threshold

A numeric value specifying the speed threshold, or "auto".

  • If numeric: Observations with speeds greater than this value will have their x, y, and confidence values replaced with NA

  • If "auto": Sets threshold at mean speed + 3 standard deviations

Value

A data frame with the same columns as the input data, but with values replaced by NA where the speed exceeds the threshold.

Details

The speed is calculated using the calculate_kinematics function, which computes translational velocity (v_translation) and other kinematic parameters. When using threshold = "auto", the function calculates the threshold as the mean speed plus three standard deviations, which assumes normally distributed speeds.

Examples

if (FALSE) { # \dontrun{
data <- dplyr::tibble(
  time = 1:5,
  x = c(1, 2, 4, 7, 11),
  y = c(1, 1, 2, 3, 5),
  confidence = c(0.8, 0.9, 0.7, 0.85, 0.6)
)

# Filter data by a speed threshold of 3
filter_by_speed(data, threshold = 3)

# Use automatic threshold
filter_by_speed(data, threshold = "auto")
} # }