adj_position function

Adjust Marker Positions Towards Center

Adjusts the positions of markers by moving them towards a specified center position within each timeframe by a specified distance. The center (centroid) can be determined by one of two methods:

adj_position(data, distance = 1, centroid = "Average")

Arguments

• data: A data frame where each row represents a marker at a specific timeframe, with columns 'Timeframe', 'Marker', 'X', 'Y', 'Z'.
• distance: Numeric value indicating the distance to adjust markers towards the center (default is 1 cm).
• centroid: A character string specifying the method to compute the centroid. Either "average" (default) or "convex hull".

Returns

A data frame of the same dimensions as data, containing the adjusted marker coordinates.

Details

1. "average" (default): The centroid is computed as the mean of all marker coordinates in each timeframe.
2. "convex hull" : The centroid is computed using a convex hull-based approach, representing a geometrically derived center.

When centroid = "average", the centroid is simply the mean of X, Y, and Z for all markers within each timeframe. When centroid = "convex hull", the centroid is computed using a convex hull-based method to identify a more geometrically relevant center.

Examples

data("sample_data")
reformat_data <- reformat_marker_data(head(sample_data))

# Using the average centroid (default)
adjusted_data_avg <- adj_position(reformat_data, distance = 1, centroid = "average")
head(adjusted_data_avg)

# Using the convex hull centroid
adjusted_data_ch <- adj_position(reformat_data, distance = 1, centroid = "convex hull")