ScatterChart

scatterChart · Charts · interactive

Charts: a scale, its ticks, and a line or area drawn from data.

Import

#include "gbui/widgets/chart.hpp"

Example

Nothing is downloaded until you press it.

ScatterResult scatterChart(Ui& ui, const Interaction& input, std::string_view id, const std::vector<PointSeries>& series, const ScatterOptions& options = {});

Points on two continuous scales — a scatter, or a bubble chart when the points carry weights. The first chart here with a real x scale. Every other one indexes its samples along the bottom: sample 0 at the left, sample n at the right, evenly spaced whatever their x values are. That is right for a series over time and wrong for a correlation, where the whole question is where the points sit against each other on both axes. Hit testing is by distance to the nearest dot rather than by column, because a scatter has no columns — two points can share an x and mean different things.

API

ScatterOptions

Option	Type	Default	What it does
xScale	Scale	0.0, 0.0	Fixed bounds for each axis. Left alone, both come from the data.
yScale	Scale	0.0, 0.0	As above, for the other one.
autoScale	bool	true
tickCount optional	std::optional<int>
axisWidth optional	std::optional<float>
height	float	220.0f
grid optional	std::optional<bool>
hover	bool	true
valueFormat	std::string_view	"%.0f"
xFormat	std::string_view	"%.0f"	The same, for the x value. Two formats because the axes are two different quantities — seconds against dollars.
xAxis	float	20.0f	Room under the plot for the x labels. Zero draws none.
minRadius	float	5.0f	The radii the weights are spread across, when there are weights.
maxRadius	float	26.0f
fillAlpha	float	0.6f	How solid a dot is. Under one on purpose: overlapping points then read as denser rather than hiding each other, and density is most of the information in a crowded scatter.
hitRadius	float	14.0f	How near the pointer has to be, in pixels, to pick a dot.
tooltip	ChartTooltip
legend	ChartLegend
name	std::string_view		What the chart is of — "Revenue by month". A chart is the one thing on a screen a reader gets nothing from: the shapes carry all of it, and the numbers behind them are the caller's. A name and a Figure role are the least that makes it navigable, and they are not the whole answer — see the note in docs/reference/accessibility.