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mingo

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MongoDB query language for in-memory objects

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function stddev(data, sampled = true) { const sum = data.reduce((acc, n) => acc + n, 0); const N = data.length || 1; const avg = sum / N; return Math.sqrt( data.reduce((acc, n) => acc + Math.pow(n - avg, 2), 0) / (N - Number(sampled)) ); } function covariance(dataset, sampled = true) { if (!dataset) return null; if (dataset.length < 2) return sampled ? null : 0; let meanX = 0; let meanY = 0; for (const [x, y] of dataset) { meanX += x; meanY += y; } meanX /= dataset.length; meanY /= dataset.length; let result = 0; for (const [x, y] of dataset) { result += (x - meanX) * (y - meanY); } return result / (dataset.length - Number(sampled)); } export { covariance, stddev };