Changelog

All notable changes to Datajure will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

Unreleased

2.0.7 - 2026-04-17

Added

• qtile quantile grouping for :by. core/qtile is the :by-friendly companion to #dt/e (cut ...) -- produces an equal-count bin assignment from a column's distribution, computed once from the dataset before grouping. Use it when you want to group by quantile rather than derive a column of quantile bins:

  ;; Quintile buckets of market cap
  (core/dt stocks :by [(core/qtile :mktcap 5)]
           :agg {:n core/nrow :mean-ret #dt/e (mn :ret)})
  ;; Result column is auto-named :mktcap-q5
  
  ;; Per-date size quintiles combined with an exact key
  (core/dt stocks :by [:date (core/qtile :mktcap 5)]
           :agg {:mean-ret #dt/e (mn :ret)})
  

  Inspired by R's cut and Stata's xtile; named to evoke quintile/decile. Companion to xbar (equal-width bins) with a symmetric API. Result column name defaults to <col>-q<n>, overridable via :datajure/col metadata (the same extension point xbar uses). nil inputs form their own group (nil key). The :from option that cut supports for reference-subpopulation breakpoints is not yet available on qtile -- a future enhancement.

Changed

• by->group-fn now receives the dataset. Internal refactor: the private by->group-fn helper takes the dataset as a parameter so that :by markers requiring population-level statistics (like qtile) can precompute their breakpoints before grouping. Both call sites (apply-group-agg, apply-group-set) have been updated. No user-visible behaviour change.

Testing

• Test count: 267 -> 273 (+6 new deftests, +17 assertions). CI subset: 200 -> 206. All passing.

2.0.6 - 2026-04-17

Added

• :within-order with :agg. :within-order can now be combined with :agg (with or without :by), sorting rows within each partition (or across the whole dataset) before aggregation. This enables order-sensitive aggregations like OHLC bar construction in a single dt call:

  (core/dt trades
    :by [:sym]
    :within-order [(core/asc :time)]
    :agg {:open  #dt/e (first-val :price)
          :close #dt/e (last-val :price)
          :vol   #dt/e (sm :size)
          :n     core/N})
  

  Previously this required two dt calls (pre-sort via :order-by, then aggregate). The restriction that :within-order required :set has been relaxed to ":within-order requires :set or :agg."

• nrow alias for N. core/nrow is now exported alongside core/N as a more discoverable full-name alternative for row counting in :agg. Both are equivalent.

Changed

• clean-column-names is now Unicode-aware. The regex that strips non-identifier characters no longer removes CJK, Cyrillic, Greek, accented Latin, and other non-ASCII letters and digits. Mixed-script column names like "Some Name (HKD millions)!" combined with CJK or accented-Latin characters are now preserved intact; only punctuation, whitespace, and symbols are replaced. Pure-ASCII column names behave exactly as before. See clean-column-names-unicode in the test suite for coverage of CJK, accented Latin, and mixed-script cases.

Fixed

• Edit-distance algorithm for typo suggestions. The Levenshtein implementation in both core.clj (column-name suggestions) and expr.clj (op-name suggestions) was producing incorrect edit distances (e.g., "kitten" to "sitting" returned 5 instead of 3), causing many legitimate suggestions to be dropped. The algorithm has been replaced with a correct Damerau-Levenshtein implementation that also treats single adjacent transpositions as distance 1. Typos like :hieght now correctly suggest :height.
• win/ratio no longer propagates Infinity on zero denominators. When the previous row's value is zero, win/ratio now returns nil rather than Infinity. This matches the div0 philosophy and gives the correct result for the canonical simple-return idiom (- (win/ratio :price) 1) -- a zero-price observation now yields nil for the next row's return, signalling "exclude" rather than contaminating downstream calculations.

Developer experience

• :agg plain-function footgun detection. Plain functions passed to :agg receive the group dataset, so #(:mass %) returns a column vector rather than a scalar -- a common mistake for users coming from :set context. Previously this silently produced nonsensical output (a column inside each result cell); now it throws a structured error with guidance pointing to either #(dfn/mean (:mass %)) or the preferred #dt/e (mn :mass).
• Unknown ops in #dt/e produce structured errors with suggestions. A typo like #dt/e (sqrt :x) previously caused a raw ClassCastException at runtime. It now throws an ex-info at read time with the suggestion: Unknown op `sqrt` in #dt/e expression. Did you mean: `sq`?. Namespaced ops (win/*, row/*, stat/*) get namespace-aware suggestions: win/mvag -> win/mavg, stat/standardise -> stat/standardize.

Testing

• Test count: 193 -> 200 (+7 new deftests, +72 assertions). All passing.

[2.0.5] and earlier

Earlier versions are not documented in this changelog. Release history is tracked in the GitHub releases page and in PROJECT_SUMMARY.md's phase-completion table.