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 value field can be a calculated field whose formula is evaluated on
the sums of the fields it names for each report cell (Excel's documented
semantics). Command to add/change/delete, dialog from the field pane,
XLSX cacheField formula round trip.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Each header was checked against every name before it, once per suffix
tried, so a source whose headers repeat (a row of thousands of equal
labels, such as check boxes) took cubic time: 4,000 columns took 28 s
in Recommended PivotTables, and a row of 16,384 hung the app, in
PivotTables, in Insert Table and in Get Data from Table/Range. Taken
names and the next suffix of each header are now kept in hash maps, in
the pivot source, in table creation and in the XLSX pivot cache; the
names are the same as before.
neilcawseandClaude Opus 5.5
Brandon Thomas
vangel76andClaude Opus 5.5
Harrison O'Connor-Hoover
nihilist-narwhal