Chart¶

Render the active table as an interactive chart. Charts open as their own tabs so you can keep the source table open side-by-side and have several charts of the same data running at once.

Trigger via:

Analyse → Chart in the toolbar
F5

The entry is hidden on string-only tables since there's nothing to plot.

Chart tab

Chart kinds¶

Pick the chart kind in the leftmost combo of the control bar. Each kind expects a specific column shape:

Kind	X column	Y column(s)	Notes
Histogram	Numeric / Date / DateTime	(none)	Frequency count of X values, binned via Sturges' rule.
Bar	Categorical (or numeric)	One or more numeric	Groups rows by X, aggregates Y(s) via the chosen aggregation.
Line	Numeric / Date / DateTime	One or more numeric	One polyline per Y column. Points auto-sort by X.
Scatter	Numeric / Date / DateTime	One or more numeric	Disconnected point cloud, one series per Y column.
Box	(none)	One or more numeric	Tukey 5-number summary per Y column.

Dates on the axes¶

Date columns are internally charted as days since 1970-01-01 and DateTime columns as seconds since the Unix epoch, but the X-axis tick labels are formatted back into dates (YYYY-MM-DD for Date, YYYY-MM-DD HH:MM:SS for DateTime). So a histogram of a date column shows 2024-01-01 / 2024-01-15 / 2024-02-01 on the X axis rather than the raw 19723 / 19737 / 19754 values. The same formatting applies to Line, Scatter, and the exported PNG / SVG / PDF.

Supported parse formats: ISO YYYY-MM-DD, dotted European DD.MM.YYYY, slashed European DD/MM/YYYY, slashed US MM/DD/YYYY. For timestamps add the time component (YYYY-MM-DD HH:MM:SS, ISO T separator, optional fractional seconds, optional trailing Z).

Categorical X axes¶

Bar charts (always) and Line / Scatter (when X is non-numeric) treat the X column as categories. Each unique value gets one tick labelled with the category name, in first-seen order. So a bar of country → population shows DE / US / JP / ... on the X axis, not 0 / 1 / 2 / .... Box plots use the Y column names as their X-axis labels.

There's a configurable cap on distinct categories (chart_max_categories, default 250). Above it the chart refuses to draw and shows an inline error asking you to filter or aggregate the table first.

For Line with categorical X, points sit at category indices in encounter order and the line connects them left-to-right. The result has the same shape as the Bar would draw, just stroked instead of filled.

Bar aggregations¶

Aggregation	What it does
Sum	Add up every Y value in the group.
Avg	Arithmetic mean of every Y value in the group.
Count	Number of rows in the group (ignores Y values).
Min / Max	Smallest / largest Y value in the group.

Histogram bins¶

Default: Sturges' rule (ceil(1 + log2(n)), clamped to [5, 50]). Untick Auto (Sturges) to set the bin count by hand (1 to 250).

Customise¶

The Customise collapsible exposes presentation knobs:

Title: free text rendered above the plot. Empty = no title.
X-axis label: overrides the column name. Empty = use the column name.
Y-axis label: same idea.
Legend: Off / Top-left / Top-right / Bottom-left / Bottom-right.
Grid: tick Show grid lines to render the background grid; untick for a clean white plot area.
Series: per-Y-column Label override (used in legend + tooltip) and a custom Colour picker (tick Custom to override the auto-cycled palette colour).

X axis¶

A dedicated X axis sub-section under Customise, mirroring the Y axis controls so you can clamp either dimension:

Control	What it does
Min / Max	Force fixed left / right bounds. Both must be set; a half-set range is ignored. Leave blank to auto-fit. For Date axes the bound is in days since 1970-01-01; for DateTime axes in seconds since the Unix epoch.
Step	Custom grid step in original-data units. Empty = let `Octa` pick.

Categorical Bar and Box charts treat the bounds as category indices (0, 1, 2, …), so you can zoom into a slice of bars by setting Min / Max.

Y axis¶

A dedicated Y axis sub-section under Customise:

Control	What it does
Min / Max	Force fixed lower / upper bounds. Both must be set; a half-set range is ignored. Click Auto to reset.
Step	Custom grid step in original-data units. Empty = let `Octa` pick.
Integers only	Format Y-axis ticks as whole numbers (no `.0` suffix). Useful for counts.
Log scale	Apply `log10(...)` to the Y values before plotting. Non-positive values drop silently. The axis label gets a `(log10)` suffix and the tick formatter renders the original magnitudes (e.g. `100`, `1000`).

When Min / Max are set with log scale on, the bounds are interpreted in original-data units and projected into log10 space internally. Type 10 and 10000 to get the familiar three-decade range without doing the maths.

Sampling¶

Histogram, Line, and Scatter are subject to chart_max_points (default 100,000). Above the cap the chart evenly-spaces samples and a pill above the plot reads Sampled 100,000 of 5,000,000 rows.

Bar and Box always work off the full input. Bar can afford to because it aggregates per category anyway, and Box because the 5-number summary is cheap regardless of row count.

Even-spaced sampling will miss outliers. The right answer is to filter first and then chart, or to bump the cap if you have the memory.

Exporting¶

Three buttons sit on the right of the row above the plot:

Button	What you get
Export PDF	One-page PDF rendered from the chart's SVG via `svg2pdf`. Print-quality vector.
Export PNG	2x retina-resolution PNG (1600 x 1000 pixels) rendered by `resvg` from the same SVG.
Export SVG	The hand-emitted SVG file directly. Editable in Inkscape / Illustrator, embeddable in web pages.

All three formats are derived from the same SVG so they look the same regardless of window size or DPI. Title / axis labels / legend / per-series colours carry into every export.

Interacting with the plot¶

Gesture	Action
Drag	Pan.
Mouse wheel	Zoom in / out.
Right-drag a box	Zoom into that region.
Double-click	Reset to auto-bounds.
Hover over a point / bar	Show coordinates in a tooltip.