Codes for homology analyses of trails and its insights into perception ranges

These are the Matlab (Persistence_Analysis.m) and Python (Persistence_Analysis.py) codes, along with the free software "Trajectory_Analysis_Version4" to compute the homology persistence of a trail (fossil or modern). These codes are supplemented to the PNAS paper "Sensing the environment: the perceptual ranges of the earliest motile animals" by Zekun Wang and Tianyun Shi.

For all the codes, you need to upload the coordinates for both the trajectory (Trajectory.txt) and the boundary of the foraging patch (Patch_boundary.txt). If the coordinates are extracted via GetData Graph Digitizer, you need to remove the headers of its output files and only keep the coordinates. You can EITHER input the "sampling frequency", which is 2.678 for the benchmark, OR "trail width", which is 108.333 (pixels) for the benchmark.