Public Access
Establish one invariant across the Drawable hierarchy: x is always a numpy ndarray, y is always a list of per-channel ndarrays, and empty data is the same types with zero length. - Drawable: x starts as empty ndarray; min/max helpers return 0 on empty data instead of raising; drop contradictory isinstance(self.y, list) branches - ADC_Result/Accumulation: empty constructors build ndarray x; full constructors coerce x/y/y_square with numpy.asarray; Accumulation get_ydata/get_yerr return empty ndarrays and no longer crash on empty statistics-less accumulations - MeasurementResult: fix get_lineplotdata to return the accumulated means (previously the never-populated self.y, so the GUI line plot could never draw); remove dead float/int branches in CSV and HDF writers - Error_Result: get_xdata/get_ydata return ndarrays Add unittest coverage for the invariant, empty-state accessors, constructor coercion, line plot data, CSV output and HDF round-trip. Generated by Mistral Vibe. Co-Authored-By: Mistral Vibe <vibe@mistral.ai>