Changes in version 0.2.0 (2026-09-20)                  

  - .warning and .drift now follow one contract across all 22 detectors:
    NA means the detector cannot judge that observation yet (warm-up),
    FALSE that it is active and has not flagged drift as of that
    observation. Behaviour change: "kswin", "adwin", "seed",
    "seqdrift2", "fhddm", "fhddms" and the "mddm_*" detectors used to
    report FALSE while warming up and now report NA; "fhddms" and
    "mddm_*", which have no warning level, now give .warning = NA.
    Detections themselves are unchanged.
  - "seed" no longer has an alpha hyperparameter: the algorithm never
    read it.
  - fit(), advance(), augment() and detect_drift() now refuse data that
    already has a .warning, .drift or .phase column instead of
    overwriting it, and advance() refuses a batch whose columns differ
    from the baseline's.
  - "wstd", "ftdd", "fpdd" and "fsdd" are much faster: their
    per-observation tests use closed forms that give identical p-values.
  - Hyperparameter values are now validated when the detector is
    specified. Out-of-range values, wrong types and impossible
    combinations (e.g. "kswin" with window_size < stat_size + 2) abort
    with a clear message instead of running and returning silently wrong
    flags. drift_detector() also rejects a method that is not a single
    string.
  - drift_detector() gains seed: the stochastic detectors ("kswin",
    "seqdrift2") draw from a private random stream carried inside the
    fitted object. Results are reproducible, independent of batching,
    and the session's global RNG is no longer advanced.
  - drift_detector() gains keep (default 10000), the number of most
    recent rows retained in the history. This bounds memory and removes
    the quadratic cost of row-by-row advance(). Behaviour change:
    histories longer than 10000 rows are now truncated, so augment() on
    a fitted detector returns at most the last keep rows; use keep = Inf
    for the previous behaviour. keep = Inf and keep = 0 emit a warning
    when the detector is specified.
  - tidy(), glance() and print() report running totals stored in the
    fitted object, so they stay exact when the history is truncated.
  - Fitted detectors saved with deriva 0.1.0 must be refit.
  - deriva now declares Depends: R (>= 4.1) and imports utils, which
    "kswin" already used.
  - Two reference datasets ship with the package, credit_monitoring and
    sensor_monitoring, and the vignettes ("Getting Started with deriva",
    and the new "Distribution-Based Drift Detection") now walk through
    them instead of generating data inline.

                 Changes in version 0.1.0 (2026-08-03)                  

  - Initial CRAN release.
  - 22 drift detectors: DDM, EDDM, HDDM_A, HDDM_W, EWMA, RDDM, STEPD,
    FHDDM, FHDDMS, MDDM_A/E/G, WSTD, FTDD, FPDD, FSDD, CUSUM, KSWIN,
    ADWIN, Page-Hinkley, SEED, SeqDrift2.
  - Tidy interface: drift_detector() → fit() → advance() with augment(),
    tidy(), glance(), and autoplot() generics.
  - detect_drift() one-shot shortcut.
  - add_prediction_error() bridge from tidymodels workflows.
  - sim_drift_stream() and sim_dist_stream() for synthetic benchmarking.