Charts

Witan Presentations includes an Excel-style chart API adapted to PowerPoint. This is a Witan extension: upstream Microsoft PowerPoint Office.js does not expose chart authoring APIs.

Charts created through Witan are normal PowerPoint chart shapes with embedded workbook data. They can be opened, edited, and rendered by PowerPoint.

Supported Chart Families

Treemap, sunburst, and map charts are not currently exposed through the Witan chart extension.

Stock Charts

Stock charts support HLC, OHLC, volume-HLC, and volume-OHLC data layouts. Use the corresponding PowerPoint.ChartType.stock* value and provide date/category labels followed by the expected price and volume columns.

Modern Chart Families

Modern ChartEx families include waterfall, histogram, Pareto, funnel, and box-and-whisker charts. They use the same addChart entry point as classic chart families, with type-specific helpers for statistical binning and box-and-whisker display options.

Waterfall Charts

Waterfall charts are useful for positive and negative bridge steps. Connector lines can be controlled through chart.series.getItemAt(0).showConnectorLines.

Box and Whisker Charts

Box-and-whisker charts expose quartile calculation, inner point, outlier point, mean marker, and mean line controls through getBoxwhiskerOptions().

Create a chart

const shape = slide.shapes.addChart(PowerPoint.ChartType.columnClustered, [
  ["Quarter", "Revenue", "Margin"],
  ["Q1", 12, 0.31],
  ["Q2", 18, 0.34],
  ["Q3", 25, 0.39],
  ["Q4", 31, 0.43]
], {
  left: 72,
  top: 96,
  width: 620,
  height: 340,
  name: "Revenue Chart",
  seriesBy: "columns"
});

const chart = shape.getChart();
chart.title.text = "Revenue and Margin";
chart.legend.position = "Bottom";
chart.series.getItemAt(1).chartType = PowerPoint.ChartType.lineMarkers;
chart.series.getItemAt(1).axisGroup = PowerPoint.ChartAxisGroup.secondary;

Replace chart data

Replace embedded workbook data with an array:

chart.setData([
  ["Quarter", "Revenue"],
  ["Q1", 12],
  ["Q2", 18],
  ["Q3", 25]
], { seriesBy: "columns" });

Or point a chart to a local embedded workbook range:

chart.setDataRange("Sheet1!A1:B4", { seriesBy: "columns" });

Axes, labels, and series

chart.axes.valueAxis.title.text = "Revenue";
chart.axes.valueAxis.numberFormat = "$#,##0";
chart.dataLabels.showValue = true;

const series = chart.series.getItemAt(0);
series.name = "Revenue";
series.format.fill.setSolidColor("#2F6FED");
series.format.line.color = "#1D4ED8";

Modern chart options are available through series helpers:

const histogram = chart.series.getItemAt(0).getBinOptions();
histogram.setType(PowerPoint.ChartBinType.binCount);
histogram.setCount(5);

const box = chart.series.getItemAt(0).getBoxwhiskerOptions();
box.setShowMeanMarker(true);
box.setShowOutlierPoints(true);

Representative Renders

These screenshots are rendered by witan pptx render from Witan-authored PowerPoint decks.

Family	Witan render	Example coverage
Column		Multiple series, title, legend, value axis
Bar		Stacked bars, horizontal categories, legend
Line		Markers, smoothing, multiple series
Area		Area fills, stacking, legend
Pie		Slice geometry, percentage labels
Doughnut		Doughnut hole sizing and legend
Scatter / XY		Numeric X/Y axes and markers
Bubble		X/Y values, bubble sizes, labels
Radar		Radar markers and multiple series
Surface		Top-view surface wireframe
Stock		OHLC stock data and axes
Waterfall		Positive/negative steps and connector lines
Histogram		Histogram bins and count axis
Pareto		Sorted bars and cumulative line
Funnel		Funnel stages and labels
Box and whisker		Quartiles, whiskers, mean markers
Combo		Column and line series with secondary axis

Verification

After chart authoring or mutation, render the affected slide:

witan pptx render deck.pptx --slide 1 -o chart-slide.png

For regression checks:

witan pptx render deck.pptx --slide 1 -o before.png
# ... edit chart ...
witan pptx render deck.pptx --slide 1 --diff before.png -o diff.png

Implementation note

The PPTX chart API depends on Witan's shared chart engine. The presentation runtime uses PowerPoint chart parts and embedded chart workbooks, while the chart model and rendering code share core behavior with Spreadsheets.