39f8b275a6
Build LinkedIn thought leadership with algorithmic understanding, strategic consistency, and AI-assisted content creation. Updated for the January 2026 360Brew algorithm change. 16 agents, 25 commands, 6 skills, 9 hooks, 24 reference docs. Personal data sanitized: voice samples generalized to template, high-engagement posts cleared, region-specific references replaced with placeholders. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
63 lines
1.7 KiB
TypeScript
63 lines
1.7 KiB
TypeScript
import type { TrendDirection } from "../models/types.js";
|
|
|
|
/**
|
|
* Calculate arithmetic mean of values.
|
|
* Returns 0 for empty array.
|
|
*/
|
|
export function mean(values: number[]): number {
|
|
if (values.length === 0) return 0;
|
|
const sum = values.reduce((acc, val) => acc + val, 0);
|
|
return sum / values.length;
|
|
}
|
|
|
|
/**
|
|
* Calculate population standard deviation.
|
|
* Returns 0 for empty or single-element array.
|
|
*/
|
|
export function standardDeviation(values: number[]): number {
|
|
if (values.length <= 1) return 0;
|
|
|
|
const avg = mean(values);
|
|
const squaredDiffs = values.map((val) => Math.pow(val - avg, 2));
|
|
const variance = mean(squaredDiffs);
|
|
|
|
return Math.sqrt(variance);
|
|
}
|
|
|
|
/**
|
|
* Determine trend direction based on percentage change.
|
|
* Returns "up" if change > threshold, "down" if change < -threshold, "stable" otherwise.
|
|
* Default threshold is 5%.
|
|
*/
|
|
export function trendDirection(
|
|
current: number,
|
|
previous: number,
|
|
threshold: number = 5
|
|
): TrendDirection {
|
|
const change = percentChange(current, previous);
|
|
|
|
if (change > threshold) return "up";
|
|
if (change < -threshold) return "down";
|
|
return "stable";
|
|
}
|
|
|
|
/**
|
|
* Calculate percentage change between current and previous values.
|
|
* Returns 0 if previous is 0.
|
|
*/
|
|
export function percentChange(current: number, previous: number): number {
|
|
if (previous === 0) return 0;
|
|
return ((current - previous) / previous) * 100;
|
|
}
|
|
|
|
/**
|
|
* Calculate how many standard deviations a value is from the mean.
|
|
* Returns 0 if standard deviation is 0.
|
|
*/
|
|
export function deviationsFromMean(value: number, values: number[]): number {
|
|
const avg = mean(values);
|
|
const stdDev = standardDeviation(values);
|
|
|
|
if (stdDev === 0) return 0;
|
|
return (value - avg) / stdDev;
|
|
}
|