/**
* トレンドライン構築ヘルパー
*
* detect_patterns.ts から抽出した makeLine / findUpperTrendline / findLowerTrendline。
* 「完成ウェッジ検出」「形成中ウェッジ検出」で共用する。
*/
export interface TrendLine {
slope: number;
intercept: number;
valueAt: (idx: number) => number;
p1: { idx: number; price: number };
p2: { idx: number; price: number };
}
/** 2 点を結ぶ直線を生成 */
export function makeLine(p1: { idx: number; price: number }, p2: { idx: number; price: number }): TrendLine {
const slope = (p2.price - p1.price) / Math.max(1, p2.idx - p1.idx);
const intercept = p1.price - slope * p1.idx;
return {
slope,
intercept,
valueAt: (idx: number) => slope * idx + intercept,
p1,
p2,
};
}
/**
* 上側トレンドライン候補を生成 — 最初の1/3と最後の1/3の高値点から2点を選び、
* 許容誤差内で最も多くのタッチを持つラインを返す。
* @param splitRatio - first/last 区間比率（デフォルト 1/3、形成中は 1/2）
* @param minTouches - 最低タッチ数（デフォルト 2）
*/
export function findUpperTrendline(
highs: { idx: number; price: number }[],
startIdx: number,
endIdx: number,
tolerance: number,
maxTouchGap = 25,
splitRatio = 1 / 3,
minTouches = 2,
): TrendLine | null {
const inRange = highs.filter(h => h.idx >= startIdx && h.idx <= endIdx);
if (inRange.length < 2) return null;
const span = endIdx - startIdx;
const firstThird = inRange.filter(h => h.idx < startIdx + span * splitRatio);
const lastThird = inRange.filter(h => h.idx > endIdx - span * splitRatio);
if (firstThird.length === 0 || lastThird.length === 0) return null;
let bestLine: TrendLine | null = null;
let bestScore = -Infinity;
for (const p1 of firstThird) {
for (const p2 of lastThird) {
if (p1.idx >= p2.idx) continue;
const line = makeLine(p1, p2);
let valid = true;
let violations = 0;
for (const h of inRange) {
const lineValue = line.valueAt(h.idx);
if (h.price > lineValue + tolerance) {
violations++;
if (violations > 1) { valid = false; break; }
}
}
if (valid) {
const touchPoints: number[] = [];
for (const h of inRange) {
const lineValue = line.valueAt(h.idx);
if (Math.abs(h.price - lineValue) <= tolerance) {
touchPoints.push(h.idx);
}
}
if (touchPoints.length >= minTouches) {
touchPoints.sort((a, b) => a - b);
let maxGap = 0;
for (let i = 1; i < touchPoints.length; i++) {
const gap = touchPoints[i] - touchPoints[i - 1];
if (gap > maxGap) maxGap = gap;
}
if (maxGap > maxTouchGap) {
valid = false;
}
}
if (valid && touchPoints.length >= minTouches) {
const score = touchPoints.length + (line.slope < 0 ? 1 : 0);
if (score > bestScore) {
bestScore = score;
bestLine = line;
}
}
}
}
}
return bestLine;
}
/**
* 下側トレンドライン候補を生成 — 最初の1/3と最後の1/3の安値点から2点を選び、
* 許容誤差内で最も多くのタッチを持つラインを返す。
* @param splitRatio - first/last 区間比率（デフォルト 1/3、形成中は 1/2）
* @param minTouches - 最低タッチ数（デフォルト 2）
*/
export function findLowerTrendline(
lows: { idx: number; price: number }[],
startIdx: number,
endIdx: number,
tolerance: number,
maxTouchGap = 25,
splitRatio = 1 / 3,
minTouches = 2,
): TrendLine | null {
const inRange = lows.filter(l => l.idx >= startIdx && l.idx <= endIdx);
if (inRange.length < 2) return null;
const span = endIdx - startIdx;
const firstThird = inRange.filter(l => l.idx < startIdx + span * splitRatio);
const lastThird = inRange.filter(l => l.idx > endIdx - span * splitRatio);
if (firstThird.length === 0 || lastThird.length === 0) return null;
let bestLine: TrendLine | null = null;
let bestScore = -Infinity;
for (const p1 of firstThird) {
for (const p2 of lastThird) {
if (p1.idx >= p2.idx) continue;
const line = makeLine(p1, p2);
let valid = true;
let violations = 0;
for (const l of inRange) {
const lineValue = line.valueAt(l.idx);
if (l.price < lineValue - tolerance) {
violations++;
if (violations > 1) { valid = false; break; }
}
}
if (valid) {
const touchPoints: number[] = [];
for (const l of inRange) {
const lineValue = line.valueAt(l.idx);
if (Math.abs(l.price - lineValue) <= tolerance) {
touchPoints.push(l.idx);
}
}
if (touchPoints.length >= minTouches) {
touchPoints.sort((a, b) => a - b);
let maxGap = 0;
for (let i = 1; i < touchPoints.length; i++) {
const gap = touchPoints[i] - touchPoints[i - 1];
if (gap > maxGap) maxGap = gap;
}
if (maxGap > maxTouchGap) {
valid = false;
}
}
if (valid && touchPoints.length >= minTouches) {
const score = touchPoints.length + (line.slope < 0 ? 1 : 0);
if (score > bestScore) {
bestScore = score;
bestLine = line;
}
}
}
}
}
return bestLine;
}
