@fusedashlabs/ui9000-workspace/dist/tool/payload/histogram-chart.js

UI9000 workspace MCP. One tool, show_workspace, draws a chart from your table. Set TYPESAFE_API_KEY to let Jev choose the chart.

import { numericColumn } from './rows.js';
/**
 * Histogram object from mcp-ui generate_histogram_chart.
 * yAxe is always empty. xAxe is the one binned column.
 * groupBy stays empty: a histogram of one variable is not a grouped chart,
 * and groupBy must not repeat xAxe.
 * data is one root whose histogramResults use _id as an object, never a string.
 */
export function histogramChartPayload(chartType, fields, rows) {
    const field = fields.distribution ?? fields.metric;
    if (!field || field === fields.groupBy || field === fields.series)
        return null;
    const values = numericColumn(rows, field);
    if (!values)
        return null;
    const bins = histogramBins(values);
    if (bins.length === 0)
        return null;
    const min = Math.min(...values);
    const max = Math.max(...values);
    return {
        chartType: chartType || 'histogramChart',
        name: 'histogram-chart',
        xAxe: [field],
        yAxe: [],
        groupBy: [],
        uniqueValues: { [field]: bins.map((bin) => bin.label) },
        data: [
            {
                min,
                max,
                histogramResults: bins.map((bin, index) => ({
                    _id: { [field]: bin.label },
                    count: bin.count,
                    bucketIndex: index,
                    group: field,
                })),
            },
        ],
    };
}
function histogramBins(values) {
    const min = Math.min(...values);
    const max = Math.max(...values);
    if (min === max)
        return [{ label: formatBin(min), count: values.length }];
    const binCount = Math.min(8, Math.max(2, Math.ceil(Math.sqrt(values.length))));
    const width = (max - min) / binCount;
    const counts = Array.from({ length: binCount }, () => 0);
    for (const value of values) {
        let index = Math.floor((value - min) / width);
        if (index >= binCount)
            index = binCount - 1;
        counts[index] += 1;
    }
    return counts.flatMap((count, index) => {
        if (count === 0)
            return [];
        const start = min + index * width;
        const end = index === binCount - 1 ? max : min + (index + 1) * width;
        return [{ label: `${formatBin(start)}–${formatBin(end)}`, count }];
    });
}
function formatBin(n) {
    return Number.isInteger(n) ? String(n) : n.toFixed(1);
}