소스리뷰 버전 적용

backend/app/services/technical_indicators.py

@@ -29,6 +29,24 @@ def _ma(values: list, window: int) -> Optional[float]:
         return None
 
 
+def _ema(values: list, window: int) -> Optional[float]:
+    """EMA(Exponential Moving Average) 계산.
+
+    SMA 시드 → 이후 지수 가중 평균 순차 적용.
+    values 길이가 window 미만이면 None 반환.
+    """
+    try:
+        if len(values) < window:
+            return None
+        k = 2.0 / (window + 1)
+        ema = sum(values[:window]) / window
+        for v in values[window:]:
+            ema = v * k + ema * (1 - k)
+        return ema
+    except Exception:
+        return None
+
+
 def _passes_uptrend(closes: list, ma_short: int = TREND_MA_SHORT, ma_long: int = TREND_MA_LONG, tol: float = TREND_TOLERANCE_PCT) -> Optional[bool]:
     if not closes or len(closes) < max(ma_short, ma_long):
         return None