Extern :

- aggiunto FIST 6.8 ( già modificato per integrazione nelle nostre librerie).

fist/Include/coreatan2.h

@@ -0,0 +1,55 @@
+inline double atan2(const double &y, const double &x) 
+{
+	if( fabs(x) >= fabs(y) )
+	{
+		// Sector to the right
+		if( x > 0 )
+		{
+			const double phi = y/x;
+			return atan(phi);
+		}
+		// Sector to the left
+		else if( x < 0 )
+		{
+			const double phi = y/x;
+			if( y >= 0) {
+				return  atan(phi) + M_PI;
+			} else {
+				return atan(phi) - M_PI;
+			}
+		}
+		// Hence, x and y are zero
+		else
+		{
+			return 0.0;
+		}
+	}
+	else if( fabs(y) >= fabs(x) )
+	{
+		// Sector to the top
+		if( y > 0 )
+		{
+			const double phi = x/y;
+			return M_PI_2 - atan(phi);
+		}
+		// Sector to the bottom
+		if( y < 0 )
+		{
+			const double phi = x/y;
+			return - M_PI_2 - atan(phi);
+		}
+		// Actually, the impossible case, x=y=0. Should be catched above.
+		else
+		{
+			assert(false);
+			return 0.0;
+		}
+
+	}
+	// This can only happen, if x or y is NaN.
+	else
+	{
+		return 0.0;
+	}
+}
+