test_velocity {QuAnTeTrack}R Documentation

Test for differences in velocity means with pairwise comparisons

Description

test_velocity() evaluates differences in velocity means across different tracks using a specified statistical test. It includes options for ANOVA, Kruskal-Wallis test, and Generalized Linear Models (GLM), and checks for assumptions such as normality and homogeneity of variances. For datasets with more than two tracks, it performs pairwise comparisons to identify specific differences between tracks.

Usage

test_velocity(data, trackvel, plot = FALSE, analysis = NULL)

Arguments

data

A track R object, which is a list consisting of two elements:

  • Trajectories: A list of interpolated trajectories, where each trajectory is a series of midpoints between consecutive footprints.

  • Footprints: A list of data frames containing footprint coordinates, metadata (e.g., image reference, ID), and a marker indicating whether the footprint is actual or inferred.

trackvel

A track velocity R object consisting of a list where each element corresponds to a track and contains velocity or relative stride length data.

plot

A logical value indicating whether to plot a boxplot of velocities by track (default is FALSE).

analysis

A character string specifying the type of analysis: "ANOVA", "Kruskal-Wallis", or "GLM". Default is "ANOVA".

Details

The test_velocity function performs the following operations:

Value

A list with the results of the statistical analysis and diagnostic tests:

Logo

Logo.png

Author(s)

Humberto G. Ferrón

humberto.ferron@uv.es

Macroevolution and Functional Morphology Research Group (www.macrofun.es)

Cavanilles Institute of Biodiversity and Evolutionary Biology

Calle Catedrático José Beltrán Martínez, nº 2

46980 Paterna - Valencia - Spain

Phone: +34 (9635) 44477

See Also

tps_to_track, velocity_track

Examples

# Example 1: Test for Differences in Velocity Means with Pairwise Comparisons in Trajectories
# in MountTom dataset.

# Hip heights for each track in the MountTom dataset
H_mounttom <- c(
  1.380, 1.404, 1.320, 1.736, 1.364, 1.432, 1.508, 1.768, 1.600, 1.848,
  1.532, 1.532, 0.760, 1.532, 1.688, 1.620, 0.636, 1.784, 1.676, 1.872,
  1.648, 1.760, 1.612
)

# Calculate velocities using the default Method "A"
V_mounttom <- velocity_track(MountTom, H = H_mounttom)

# Test for Differences in Velocity Means with Pairwise Comparisons
test_velocity(MountTom, V_mounttom)

# Example 2: Test for Differences in Velocity Means with Pairwise Comparisons in Trajectories
# in PaluxyRiver dataset.

# Hip heights for each track in the PaluxyRiver dataset
H_paluxyriver <- c(3.472, 2.200)

# Specify different methods for different tracks
Method_paluxyriver <- c("A", "B")

# Calculate velocities using specified methods
V_paluxyriver <- velocity_track(PaluxyRiver, H = H_paluxyriver, method = Method_paluxyriver)

# Test for Differences in Velocity Means with Pairwise Comparisons
test_velocity(PaluxyRiver, V_paluxyriver)


[Package QuAnTeTrack version 0.1.0 Index]