Inputs and scientific fits

File is not recognised

Export a text table with either one parseable timestamp column, separate date and time columns, or increasing elapsed hours in the first column. Keep at least three data rows and a numeric activity-like column. Do not rename a proprietary binary file to CSV.

Missing dates or synthetic origin

Elapsed-time records deliberately receive a synthetic origin. Period, synchrony, coupling, and many fitted analyses remain meaningful; calendar light schedules and absolute zeitgeber alignment do not. Use a timestamped export for phase-angle work.

Sampling is insufficient

Widen the selected interval, reduce exclusions, or supply more observations. Do not lower a minimum simply to force a fit if the resulting window no longer represents the scientific question.

Periods disagree or form harmonics

Inspect the raw actogram and profile, check whether one value is half or twice another, and widen the record rather than the search range. Run instantaneous phase if a changing period is plausible.

A fit fails

Read the result's named condition: missing pre/post days, no amplitude, insufficient phase coverage, singular positions, or absent fitted parameters. Correct that input. A refusal is preferable to a numerical object with no defined meaning.