A category range two or more columns wide beside a column of values (year beside month, Excel's
multiLvlStrRef) was read as one flat list: 36 rows in two columns became 72 categories, the
series sat in the left half of the plot and the years and months shared one row of labels.
Saving wrote the range as a plain strRef, so Excel lost the two-level axis too.
- gridcraft_core::category_levels: the shape of a category range beside its values (levels are
columns when the points run down the rows, rows when they run along the columns; up to three
outer levels), shared by the chart and xlsx crates.
- ChartData.category_levels: the outer levels, nearest the labels first, one entry per category,
non-empty where a group starts. resolve fills it; a single column is unchanged.
- render: the outer levels in rows under the labels, a group's name centred under its categories
with a separator at each boundary; in bar charts in columns beside the labels.
- xlsx: <c:cat> written as multiLvlStrRef with the level caches (innermost first), so the axis
survives a round trip.
Tests in core (shapes), chart (resolve and layout for columns, bars and a row of values) and
xlsx (written XML, read-back, stability, a single column stays strRef). chart-parity, gaps § 4
and the ROADMAP progress log updated.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Model: Series.trendlines (Vec<Trendline>, serde default) with kind
(linear, exponential, logarithmic, polynomial 2..6, power, moving
average 2..255), name, forward/backward forecast, set intercept,
equation / R² display and line colour, width and dash.
XLSX: read and write <c:trendline> in CT_Trendline child order, placed
after dLbls and before the data references in line, bar, area, scatter,
bubble and stock series; unknown types are skipped.
Chart: least-squares fits (transformed for exp/log/power, skipping
non-positive values; polynomials via normal equations on centred,
scaled x with partial pivoting), moving averages, forecasts that widen
the category or x axis, clipping to the plot, equation and R² labels and
legend entries ("Linear (Sales)"). Degenerate data draws nothing.
Engine: chart.addElement element="trendline" adds (type, series, order,
period, forward, backward, displayEquation, displayRSquared) or removes
trendlines; document.inspect lists each chart's trendlines.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A chart linked to a PivotTable: series are built from the report
(innermost row items x column items/value fields, totals excluded) and
rebuilt on every refresh or layout change; c:pivotSource round trip;
chart series accept union references.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A line chart from numeric X values (years) plotted them as a series and
there was no way to set the axis labels. Now:
- a blank top-left cell over a header row makes the first column the
category labels even when it holds numbers (the usual convention);
- chart.selectData takes categories (Horizontal (Category) Axis Labels,
"" clears) and removeSeries, and range is optional;
- Chart Design gets a Select Data button opening a Select Data Source
dialog: chart data range, legend entries with Remove, axis labels.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The ribbon button inserted a column chart straight away. It now opens an
Insert Chart dialog: a Recommended tab (insert.chartRecommendations, a
heuristic over the data's shape: series, points, labels, negatives) and an
All Charts tab, each with a live preview of the chart for the selection.
OK inserts the chosen type and selects the chart.
insert.recommendedCharts stays dialog-free for programmatic calls: without
a type it inserts the first recommendation; type/subtype pick one.
insert_chart is split into build_chart (also used for previews).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The corner drag now grabs the chart where the press began and the selected object's corner shows a resize cursor. The Format Chart Area Size fields, chart and axis title fields and the Table Name field reloaded their value from the workbook every frame, so typed or dragged edits were thrown away; they now keep a draft until the field loses focus (Escape cancels, like sheet tab rename).
Progress docs per craftrules standards/progress-docs.md: target-app parity, gaps, roadmap with alpha gate, readiness by audience (full / mainstream / essentials) with Opus 5.5 hours, and feature, format, hardware, UI and localization parity docs.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
