Changes in version 2.0.0 (2026-09-22)                  

Major changes

  - The dot-separated function names of survrec 1.x were renamed to
    snake_case: psh_fit(), wc_fit(), mlefrailty_fit(), surv_search() and
    q_search(). The old names (psh.fit(), wc.fit(), mlefrailty.fit(),
    surv.search(), q.search()) still work but emit a deprecation warning
    and will be removed in a future release. S3 methods
    (plot.survfitr(), ...) and the argument names shared with the
    survival ecosystem (conf.int, boot.F, ...) are unchanged.

  - The computational core has been rewritten from Fortran 77 to modern
    C++ (via Rcpp). The public R API (Survr(), survfitr(), psh_fit(),
    wc_fit(), mlefrailty_fit(), survdiffr(), q_search(), surv_search()
    and the S3 methods) is unchanged.

  - New maintainer: Dolors Pelegri-Siso.

  - The bootstrap (survdiffr()) now uses R's random number generator, so
    results are reproducible with set.seed(). The previous
    implementation used the non-standard GNU rand() generator, which R
    could not seed. The seed argument now defaults to NULL (use the
    current RNG state) and is honoured when supplied; in 1.2-5 it was
    silently ignored.

  - The semiparametric (gamma frailty) bootstrap of survdiffr() (boot.F
    = "semiparametric") is now available; it existed in the Fortran code
    but was disabled in the R layer.

  - mlefrailty_fit() now returns the posterior frailty estimates
    ($frailties), previously computed internally and discarded.

  - The proprietary IMSL routine ZXGSP (golden-section search) and the
    copied Netlib Brent/D1MACH code have been replaced by a clean
    implementation of Brent's minimization algorithm.

  - All fixed-size internal buffers (800 elements) have been removed;
    data size is now unlimited.

Bug fixes

  - summary() on a fit without strata no longer fails with "$ operator
    is invalid for atomic vectors".
  - wc_fit() no longer reads an undefined loop variable when counting
    events of subjects whose only gap time is censored (undefined
    behaviour in the Fortran wc2 routine).
  - The EM algorithm of mlefrailty_fit() now honours the requested
    convergence tolerance tol. In 1.2-5 the inner alpha search overwrote
    it with 1e-4 after the first iteration and computed part of the
    convergence criterion in single precision, so estimates may differ
    slightly (they are now more accurate).
  - The 7-seed retry loop of mlefrailty_fit() is now really executed
    when the EM does not converge (a status-flag bug made it dead code).
  - survdiffr() no longer fails when boot.G or seed are supplied
    together with a grouping formula (they leaked into the model frame).
  - q_search() returns NA with a warning (instead of failing) when the
    survival estimates are unavailable.
  - wc_fit() now reports m as the number of recurrences per subject,
    consistently with psh_fit(); it previously counted the censored
    record as well.
  - Several plot, summary and q_search internals accessed $surv relying
    on partial matching; they now use the actual component name.

New features

  - New ggplot2 graphics sharing the visual style of the companion
    package gcmrec: autoplot() methods for survival fits (with fun =
    "surv"/"event"/"cumhaz" and pointwise log-log confidence bands),
    plotEstimators() to overlay the three estimators on the same data,
    autoplot() for mcf and grouped survdiffr results, and the exported
    theme_survrec(). The base-graphics plot()/lines() methods are kept
    for backwards compatibility.

  - New mcf(): Nelson-Aalen type estimate of the mean cumulative
    function (expected number of events by calendar time), optionally by
    group.

  - New quantile() and as.data.frame() methods for survfitr objects.

  - Grouped survdiffr() results now have class survdiffr with a
    summary() method that reports percentile bootstrap intervals per
    group and pairwise differences of quantiles with bootstrap p-values
    (the per-group elements keep class boot, so boot::boot.ci() keeps
    working).

  - Fits no longer depend on the ordering of the input rows: subjects
    are regrouped by order of first appearance. In 1.2-5 the estimators
    silently misaligned subjects and gap times when the ids did not
    appear in sorted, contiguous blocks.

  - Survr() now checks that every subject has exactly one censored time
    (the old check could be fooled by compensating subjects).

  - The bootstrap re-estimation of survdiffr() runs in parallel with
    OpenMP when available. The number of threads is controlled with the
    new survrecThreads() function (default: let OpenMP decide, honouring
    OMP_NUM_THREADS). Resampling stays serial on R's RNG, so results are
    identical for any number of threads.

  - plot.survfitr() no longer draws meaningless confidence bands when
    the fit provides no standard errors or conf.int = FALSE is given.

Infrastructure

  - Registered native routines via Rcpp; DESCRIPTION uses Authors@R;
    documentation migrated from hand-written latin1 .Rd files to
    roxygen2 (UTF-8), with the NAMESPACE generated by roxygen2.
  - R sources reorganized into one file per exported function;
    interpreted code vectorized (colSums(), rowsum(), findInterval()
    replace explicit loops and outer()/apply() constructions).
  - Regression test suite (testthat) validating the C++ port against
    reference values generated with the original Fortran implementation
    (see tools/build-reference-fits.R).