Changelog

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

[0.4.0] - 2026-04-19

Candlestick (OHLC) series — first-class GnuplotEx.candlestick/1,2,3 builder for financial charts. Supports bull/bear body coloring via :up_color/:down_color (conditional lc rgb variable) and optional wick caps via :whiskerbars
MultiPlot composition — new %GnuplotEx.MultiPlot{} struct plus GnuplotEx.multiplot/0,1, add_panel/2, layout/2, shared_x/2 builders for multi-panel layouts (e.g. price + volume + indicator stacks). Shared x-axis mode aligns time-series panels
MultiPlot figure-level styling — :background (canvas color appended to set terminal) and :commands (figure-level raw gnuplot commands emitted before set multiplot) for consistent styling across panels
MultiPlot :row_heights — unequal vertical panel heights (e.g. [0.6, 0.2, 0.2] for price-dominant financial stacks). Emits bare set multiplot with per-panel set size/set origin instead of forced-equal set multiplot layout R,C
LiveView accepts MultiPlot — <.live_gnuplot plot={@multiplot} /> renders composed layouts through the existing component, cache, and async paths

Series.using honored for all data sources — previously dropped for inline "-" and datablock $name sources, breaking time-axis line/impulses/steps plots that gnuplot requires to declare their using clause
Multiplot inline-streaming — gnuplot 6 refuses plot '-' inside set multiplot. Panel series data is now hoisted into named datablocks ($mp_pN_sM << EOD … EOD) before emission
Float-tuple ranges — {94.5, 105.5} now renders as [94.5:105.5] instead of 94.5,105.5 (invalid gnuplot syntax). Elixir Range doesn't support floats, so float tuples are emitted as gnuplot range literals directly
Duplicate SVG ids in LiveView — multiple <.live_gnuplot> components on one page no longer collide on gnuplot's hardcoded ids (gnuplot_canvas, gpPt0–gpPt14, textbox, greybox, etc.). The component rewrites every id=/xlink:href=#/href=#/url(#…) to a per-component prefix, handling both single- and double-quoted forms

Real-gnuplot smoke tests (@tag :gnuplot) added for multiplot, candlestick, and the using/range fixes so future regressions fail on render rather than slipping past dry-mode checks

render/2 now returns actual SVG/PNG output - Previously returned the gnuplot script string instead of rendered output, breaking LiveView components
datablock/3 works with command/2 plots - Named datablocks are now defined before custom commands, allowing references like $stats in custom plot commands
Pie/donut charts render correctly - Fixed inner_radius calculation so pie charts display as full circles, not donuts

Pie/donut slice labels - Labels are now rendered at the center of each slice using set label commands

Initial public release
High-level API for common chart types (scatter, line, bar, histogram, pie, donut, spider, parallel coordinates)
Low-level API for full gnuplot control
LiveView components for real-time charts
Explorer DataFrame integration
Nx tensor support
ML visualizations (confusion matrix, ROC curves, loss curves, embeddings)
SVG, PNG, and ASCII output formats
Async/parallel rendering
Binary data optimization for large datasets