docs: small multiples (faceted charts) configuration page

[igorlukanin]

Summary

Documents small multiples — splitting a chart into a grid of panels, one per value of a dimension.

• New page charts/configuration/small-multiples, covering the Split by picker, the six options (Columns, Axis scales, Sort panels by, Sort order, Show panel titles, Max panels), how shared vs. independent scales change what the grid is good for, how the panel cap interacts with sorting, and the limitations.
• It lives under configuration/, not chart-types/: small multiples is a setting applied to bar, line, area, and scatter charts, whereas every chart-types/ page documents one mark.
• Adds the page to the "Configure charts" index table and the docs.json nav, plus a Split by row in the series-mapping channel table.

Test plan

• docs.json parses; the new page is in the "Configure charts" group
• Every option name matches the label the user actually sees in the shipped UI
• Mintlify preview renders

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[claude]

Claude finished @igorlukanin's task in 1m 23s —— View job

---

Docs-only PR, reads well — 3 low-severity notes, all posted inline

Full review

• Read the diff
• Check docs.json nav placement & formatting
• Cross-check page conventions against docs-mintlify/CLAUDE.md and sibling pages
• Verify claims against sibling docs (chart types, series mapping)
• Post review

What's good

• Correct site — docs-mintlify, not the deprecated /docs. Frontmatter uses title/description as the conventions require.
• The {/* TODO screenshot: … */} placeholder matches the exact form used across every other page in charts/ — consistent, and invisible in the rendered output.
• Nav ordering is coherent: docs.json and the index table in configuration/index.mdx both place Small multiples after Color & stacking. No orphan page, no dangling table row.
• All three internal links are root-relative and point at real files (small-multiples.mdx exists; series-mapping back-link resolves).
• Placing this under configuration/ rather than chart-types/ is the right call, and the rationale in the PR body holds up — every chart-types/ page documents one mark, this documents a setting applied across several.
• The prose earns its length. "Shared vs. independent axis scales" gives the reader a decision rule rather than restating the dropdown, and the sorting × cap interaction is the kind of thing users hit and don't find documented.

Notes (all inline)

Severity	File	Note
Low	docs.json:89	Two page entries collapsed onto one line — breaks the one-per-line style of the whole array
Low	small-multiples.mdx:30	labelled → labeled; only British-spelling occurrence in docs-mintlify/docs
Low	small-multiples.mdx:53-55	Boxplot appears in neither the supported nor the unsupported chart-type list, though series-mapping.mdx documents it as cartesian

Not verifiable from this repo

The chart UI isn't in this repo — no source matches for small multiples / splitBy under packages/ or rust/. So the factual claims about the shipped UI (option labels, Shared as the axis-scale default, the 12-panel default cap, the 1–6 column range, legend shared across the grid) are taken on trust from the "matches the label the user actually sees" checkbox in your test plan. Nothing in the docs contradicts itself; I just can't independently confirm those values.

One optional thought: the PR title says "faceted charts" and color-and-stacking.mdx already uses "Color faceting", but the word facet never appears on the page. A single mention would help anyone searching with the Vega-Lite term.

• [Branch](https://github.com/cube-js/cube/tree/igor/cub-2940-docs-small-multiples)

[claude]

Two page entries on one line — every other entry in this pages array (and in the file generally) is on its own line. Worth splitting so future diffs on either page touch only their own line.

Suggested change

	"docs/explore-analyze/charts/configuration/color-and-stacking", "docs/explore-analyze/charts/configuration/small-multiples",
	"docs/explore-analyze/charts/configuration/color-and-stacking",
	"docs/explore-analyze/charts/configuration/small-multiples",

[claude]

labelled is the British spelling; the rest of the docs use labeled (e.g. chart-types/bar.mdx, explore-analyze/skills.mdx). This is the only occurrence of labelled in docs-mintlify/docs.

Suggested change

	| **Show panel titles** | Whether each panel is labelled with its dimension value. |
	| **Show panel titles** | Whether each panel is labeled with its dimension value. |

[claude]

Boxplot falls through both lists: series-mapping.mdx documents it as an X/Y cartesian type, but it appears neither in the supported set ("Bar, line, area, and scatter") nor in the explicitly-unsupported one. If boxplot can't be split, adding it to the second list closes the gap; if it can, the supported list (and the Split by row in series-mapping.mdx) needs it.

[claude]

Claude finished @igorlukanin's task in 1m 19s —— View job

---

Re-review of the new commit — the clarification is a net improvement; 3 prior threads still open, 1 new nit

Full review

• Diff the new commit against the previously reviewed state
• Re-check the three prior unresolved threads
• Verify style conventions against sibling chart pages
• Post inline note, update summary

What the new commit changes

94bb898 touches only small-multiples.mdx, and it's a genuine correctness fix:

• Axis scales row: "share one set of axes" → "drawn against the same scale". The old wording implied Shared collapses the grid to one outer axis pair, which is a different (and wrong) claim than sharing a domain. Good catch.
• New sentence in Shared vs. independent axis scales stating each panel keeps its own axes either way, which pins down the thing the table row no longer has room to say.

The "Shared vs. Independent" section now reads as: what stays the same → what changes → when to switch. That's the right order.

Prior threads — all three still apply, none resolved

File	Status
docs.json:89	Unchanged — color-and-stacking and small-multiples are still on one line. Fix this →
small-multiples.mdx:30	labelled unchanged — and the new commit added a second occurrence at line 35
small-multiples.mdx:57	Boxplot still absent from both the supported and unsupported lists. chart-types/boxplot.mdx:31-32 confirms it's an X/Y cartesian type, so the gap is real either way

I left these unresolved rather than replying on each — the unresolved state is the signal.

New note (inline, small-multiples.mdx:35)

The added sentence carries two style deviations:

• labelled — second instance of the British spelling now; docs-mintlify/docs otherwise uses labeled (chart-types/bar.mdx:76, explore-analyze/skills.mdx:28, scheduled-tasks.mdx:135).
• its own x and y axis — lowercase, and singular for two axes. Every other chart page writes X axis / Y axis capitalized (bar.mdx:12, heatmap.mdx:12, boxplot.mdx:31).

Fix both →

Still not verifiable from this repo

The chart UI isn't in this monorepo — no source matches for small multiples / splitBy under packages/ or rust/. So the new claim that panels are always individually axis-labelled in both scale modes is taken on trust, same as the option labels, the 12-panel default, and the 1–6 column range. Worth a glance at the Mintlify preview against the shipped UI, since this commit's whole purpose is to make that specific claim.

• Branch •

[claude]

Two style nits on this new sentence:

• labelled again (same British spelling as line 30) — the rest of docs-mintlify/docs uses labeled.
• x and y axis — every other chart page capitalizes these (X axis, Y axis; see chart-types/bar.mdx:12, chart-types/heatmap.mdx:12), and here it's two axes, not one.

Suggested change

	Every panel is labelled with its own x and y axis either way. What the setting changes is the scale those axes are drawn against.
	Every panel is labeled with its own X and Y axes either way. What the setting changes is the scale those axes are drawn against.