Changes in version 0.4.1 (2026-04-07)                  

Bug fixes

  - replace blanket checkmate namespace imports with selective imports
    to avoid new R-devel warnings from upstream rlang exports
    (check_string() and check_data_frame())

                 Changes in version 0.4.0 (2026-03-17)                  

New features

  - tf_register() & co implement registration methods (SRVF, affine,
    landmark, continuous-criterion) for aligning functions and analyzing
    phase variability. Returns a new tf_registration class with
    accessors tf_aligned(), tf_inv_warps(), tf_template().
  - tf_depth() now implements five functional depth methods: MBD
    (default), MHI, FM (Fraiman-Muniz), FSD (Functional Spatial Depth),
    and RPD (Regularized Projection Depth). MHI ranks functions from
    lowest (0) to highest (1); all other depths are scaled from 0 (most
    extreme) to 1 (most central). MBD is now scaled to [0, 1] instead of
    [0, 0.5].
  - tf_split() / tf_combine() for splitting functions into sub-domain
    fragments and re-combining them
  - tf_rgp() gains a "brownian_bridge" covariance option and can
    generate irregular data via the new irreg argument
  - tfb_spline() now converts fda::fd and fda::fdSmooth objects directly
  - mgcv-style Fourier basis constructor for use in tfb_spline()
  - sparklines in print() / format() for all tf subtypes
  - tf_where() now defaults to arg = tf_arg(x), consistent with other
    functions
  - as.matrix() for irregular tfd now always interpolates to a common
    grid

Bug fixes

  - tf_derive() for tfd objects now uses second-order accurate finite
    differences, preserving the original domain and grid (#59)
  - major overhaul of NA handling: NA entries are now consistently
    represented as NULL internally; fixes for tf_arg(), tf_evaluate(),
    tf_smooth(), tfd() conversion, is.na(), printing, and arithmetic
    with NA entries
  - fix summary.tf() returning wrong central range
  - fix tfd domain enforcement for length-1 data (#139)
  - fix printing for empty tfb objects and all-NA vectors

Other changes

  - tf_derive and tf_integrate can now handle tfb with non-identity link
    functions by falling back to tfd-calculus methods (and returning tfd
    objects).
  - tfd_irreg arithmetic now operates on intersection of arg-values
    instead of failing when arg-values are not identical
  - tfb arithmetic fix
  - dropped glue dependency in favour of cli / sprintf; replaced
    stopifnot() with informative cli::cli_abort() throughout
  - use vctrs::vec_arith() for group generics, vctrs utils in [.tf
  - various internal performance improvements
  - use air formatter for all R code

                 Changes in version 0.3.4 (2024-05-22)                  

  - bug fix: normalize tf_crosscov correctly

                 Changes in version 0.3.3 (2024-03-28)                  

  - tf_rebase behaves more consistently on (irregular) data with
    different lengths
  - avoid CRAN issues by streamlining tfb_fpc example and skipping
    tf_rebase tests