Function getStats

packages/sanddance-specs/src/inference.ts:93–129

(data: object[], column: Column)

}

export function getStats(data: object[], column: Column) {
    const distinctMap = {};
    const stats: ColumnStats = {
        distinctValueCount: null,
        max: null,
        mean: null,
        min: null,
    };
    let sum = 0;
    for (let i = 0; i < data.length; i++) {
        const row = data[i];
        const value = row[column.name];
        distinctMap[value] = true;
        if (stats.max === null || value > stats.max) {
            stats.max = value;
        }
        if (stats.min === null || value < stats.min) {
            stats.min = value;
        }
        const num = +value;
        if (!isNaN(num)) {
            sum += num;
        }
        if (column.type === 'string' && !stats.hasColorData && isColor(value)) {
            stats.hasColorData = true;
        }
    }
    if (column.quantitative) {
        stats.mean = data.length > 0 && (sum / data.length);
        stats.hasNegative = detectNegative(column, data);
        if (column.type === 'integer') {
            stats.isSequential = detectSequentialColumn(column, data);
        }
    }
    stats.distinctValueCount = Object.keys(distinctMap).length;
    return stats;
}

function detectNegative(column: Column, data: object[]) {
    for (let i = 1; i < data.length; i++) {