| define_day_indices | Generate sequential day indices from ISO 8601 timestamps |
| get_cadence_bands | Calculate minutes and steps spent in cadence bands |
| get_cadence_peaks | Calculate cadence peak metrics |
| isGGIRoutput | Check if a directory is a valid GGIR output folder for stepmetrics |
| readFile | Read and standardize minute-level step data for one participant |
| step.metrics | Calculate and export daily and person-level step and cadence metrics |