Bar chart single point

[abidlabs]

Renders single-value metrics as bar chart instead of line plots:

Screen.Recording.2026-03-25.at.7.21.30.PM.mov

[gradio-pr-bot]

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🦄	Changes	detected!	Details

[gradio-pr-bot]

🦄 change detected

This Pull Request includes changes to the following packages.

Package	Version
trackio	minor

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• Bar chart single point

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[HuggingFaceDocBuilderDev]

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[qgallouedec]

Looks good! I cannot really review the svelte code though 😅

[Copilot]

Pull request overview

Adds support for rendering metrics that only contain a single logged value per run as bar charts, improving readability vs. line plots for single-point series.

Changes:

• Add isSinglePoint() detection in Metrics page and switch rendering to BarPlot for those metrics.
• Introduce new BarPlot.svelte Vega-Lite component with CSV/PNG export, fullscreen, and drag-reorder support.
• Update Playwright UI test expectations and add a changeset for a minor release.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
trackio/frontend/src/pages/Metrics.svelte	Detects single-point metrics and conditionally renders BarPlot instead of LinePlot.
trackio/frontend/src/components/BarPlot.svelte	New bar chart component (Vega-Lite) for single-point metrics with toolbar + fullscreen support.
tests/ui/test_ui_display.py	Extends UI test to include a single-point metric and asserts bar plot presence.
.changeset/stupid-lions-speak.md	Declares a minor version bump for the new UI behavior.

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[Copilot]

isSinglePoint(metric) scans masterData (filter + per-run counting) and is invoked for every metric render. With many metrics/rows this becomes an O(metrics × rows) hot path on each reactive update. Consider precomputing a Map<metric, boolean> (or counts per metric/run) when masterData changes (e.g., in processFromCache or a $derived.by), and only evaluating it when plotData.length > 0 to avoid extra full scans for empty plots.

Suggested change

	{@const useBar = isSinglePoint(metric)}
	{#if plotData.length > 0}
	{#if plotData.length > 0}
	{@const useBar = isSinglePoint(metric)}

[Copilot]

CSV export builds the header as "run," + y without escaping/quoting y. If a metric name ever contains a comma or quote, the generated CSV will be malformed. Consider applying the same CSV escaping used for run names (and optionally values) to the header fields as well (or use fixed column names like run,value).

Suggested change

	function downloadCSV() {
	const barData = getBarData();
	if (barData.length === 0) return;
	const header = "run," + y;
	const rows = barData.map((row) => {
	const run =
	typeof row.run === "string" && (row.run.includes(",") || row.run.includes('"'))
	? `"${row.run.replace(/"/g, '""')}"`
	: row.run;
	return `${run},${row.value}`;
	function csvEscape(value) {
	if (value == null) return "";
	const str = String(value);
	return /[",\n]/.test(str) ? `"${str.replace(/"/g, '""')}"` : str;
	}
	function downloadCSV() {
	const barData = getBarData();
	if (barData.length === 0) return;
	const header = `${csvEscape("run")},${csvEscape(y)}`;
	const rows = barData.map((row) => {
	return `${csvEscape(row.run)},${csvEscape(row.value)}`;

[abidlabs]

Thanks so much for reviewing @qgallouedec! The Svelte should be fine, as it's more or less vendored in from Gradio. Fixed the issues that @copilot found as well, will merge once CI is green.