Stream graph

Centered stacked area. It sits in the Time series group of the widget library.

When to use it#

Use a stream graph to show the rhythm of many categories over a long period, where shape matters more than exact values: which spending categories swell in which months. Bands flow around a centre line rather than sitting on zero.

When to pick something else#

• Need to read actual amounts? Use a Stacked area; a stream graph has no value axis.
• Comparing a few categories precisely? Use a Line chart or Grouped bar.
• Only one series? It draws as a plain Area chart.

The data it needs#

Pick these in the Data tab of the inspector. BankSync suggests a column for each when your source has an obvious match.

Rows that share a category are combined before drawing: choose Sum, Average, Count, Min or Max on the value field. See Binding data.

Stream graph options#

This chart has no options of its own; everything on its Style tab is the shared chart styling below.

Shared chart styling#

Every chart also has the shared styling options. These apply to this one:

• Legend: position, layout and which series show.
• Axes: titles, tick labels and number format.
• Grid, title, padding and background.
• Value labels on the marks.
• Categories and labels: top N with "Other", sort order, readable labels, the handwritten callout.
• Style: corner radius, line width, opacity and animation.
• Tooltip on hover.
• Click to filter: clicking a mark can filter the rest of the dashboard. See Filters and cross-filtering.
• Colours: follow the dashboard palette or pick one for this chart.

Messy data#

• The value axis is hidden, so readers rely on the tooltip for numbers; it lists each band and a Total.
• A missing value counts as zero, so a band thins to nothing for that date.
• More than 8 series: the 7 largest keep their colour and the rest merge into Other.
• Values on the same date are summed by default.
• Stream graphs are meant for positive amounts such as spending; mixing in negative values makes the shape hard to read.

On a phone#

The shape survives at full phone width, but the legend moves below the chart and many categories get cut to "+N more". On a phone, a Stacked area with fewer categories is usually clearer.

Related charts#

• Line chart: Time series over any field
• Area chart: Stacked or overlaid area
• Sparkline: Tiny inline trend
• Stacked area: Series stacked over time
• Step line: Discrete jumps over time