/**
* Center of Gravity Indicator
* Uses physics concept to find the "center of gravity" of price action
*/
import { calculateWMA } from './wma';
export function calculateCOG(closes, period = 10) {
// Minimum 3 data points required
if (closes.length < 3) {
return {
cog: null,
signal: null,
trend: null,
};
}
// Use adaptive period
const effectivePeriod = Math.min(period, closes.length);
// Calculate WMA for each sub-period from 1 to effectivePeriod
const wmaValues = [];
for (let i = 1; i <= effectivePeriod; i++) {
const wma = calculateWMA(closes, i);
if (wma.length > 0) {
wmaValues.push(wma[wma.length - 1]);
}
else {
// Fallback: use simple average
const avg = closes.slice(-i).reduce((a, b) => a + b, 0) / i;
wmaValues.push(avg);
}
}
if (wmaValues.length === 0) {
return {
cog: null,
signal: null,
trend: null,
};
}
// Calculate Center of Gravity: -∑(WMA(i) × i) / ∑WMA(i)
let numerator = 0;
let denominator = 0;
for (let i = 0; i < wmaValues.length; i++) {
const weight = i + 1; // i starts from 1 to period
numerator += wmaValues[i] * weight;
denominator += wmaValues[i];
}
if (denominator === 0) {
return {
cog: null,
signal: null,
trend: null,
};
}
const cog = -numerator / denominator;
// Determine signal (COG can be used as oscillator)
let signal = null;
const currentPrice = closes[closes.length - 1];
// Compare COG with current price (simplified signal)
const priceDiff = (currentPrice - Math.abs(cog)) / Math.abs(cog);
if (priceDiff > 0.02)
signal = 'overbought'; // Price significantly above COG
else if (priceDiff < -0.02)
signal = 'oversold'; // Price significantly below COG
else
signal = 'neutral';
// Determine trend based on COG position relative to price
let trend = null;
if (currentPrice > Math.abs(cog))
trend = 'bullish';
else if (currentPrice < Math.abs(cog))
trend = 'bearish';
else
trend = 'neutral';
return {
cog,
signal,
trend,
};
}
