For the full log of gretl changes since January 2000, see
<@url="http://gretl.sourceforge.net/ChangeLog.html">.

2021-05-04 version 2021b
- New function trigamma(): second derivative of lngamma
- New function midasmult(): gives MIDAS multipliers
- New command "bds": BDS nonlinearity test
- gdtb data format: make the new variant the default
- tighten up on defbundle() syntax: no empty arguments
  allowed
- array definition: enforce the specific choice of type
- "wls" command, with 0/1 weights: compute $yhat and $uhat
  for the excluded observations
- "dpanel" estimation via the GUI: make the --dpdstyle flag
  configurable
- "dpanel" --verbose switch: provide some information on the
  instruments used
- "adf" command: support more accurate inference with
  improved p-values or critical values, for the GLS case
  in particular
- "xtab" command: clarify that the $result (matrix) accessor
  is just for the bivariate case
- "clear" command: add --functions option to remove all hansl
  functions from memory
- "restrict" command: add "inject" keyword to support use of
  an array of strings to specify restrictions
- "param_names" keyword for nls, mle, gmm: accept an array of
  strings as argument
- binary probit and logit: offer Estrella's pseudo R-squared
  as an alternative to McFadden, via --estrella option
- The functions mean, sum, sd, var, wmean, wsd and wvar now
  accept an optional boolean argument; specific to the
  cross-sectional statistics produced when list arguments
  are given, this allows skipping of missing values.
- hdprod(): introduce "shorthand" syntax (one argument only)
- dbnomics addon: speed up retrieval of data
- user-defined functions: allow overloading of numeric
  arguments and return value (scalar, series or matrix)
- user-defined function parameters: enforce the "const" flag
  more consistently
- gretl timer ("stopwatch"): provide a separate timer for each
  level of function execution
- GUI usage of geoplot addon: make it easier to save an edited
  map as GeoJSON
- GUI model specification dialog: enable interactive search in
  lists of series
- GUI, saving contents of bundles: enable saving of integer
  members
- GUI, handle dependencies when installing function packages
- GUI script editor: improve implementation of "smart tab"
- Fix bug: breakage in computing out-of-sample forecasts from
  VECMs
- Fix bug: possible crash when displaying a matrix with very
  long column names in the GUI program
- Fix bug: broken covariance matrix from mols() with a large
  number of regressors
- Fix bug: crash on applying postfix "++" to a submatrix
- macOS: first release for arm64
