+ CalcPolygonAreaAutonavi

business/jxutils/jxutils_cms.go

@@ -495,3 +495,35 @@ func CreateQrOrBarCode(width, height int, codeType, srcData string) (imgBase64 s
 
 	return imgBase64, err
 }
+
+// 高德地图面积计算公式
+// https://blog.csdn.net/zdb1314/article/details/80661602
+func CalcPolygonAreaAutonavi(points [][2]float64) (area float64) {
+	sJ := float64(6378137)
+	Hq := float64(0.017453292519943295)
+	c := float64(sJ * Hq)
+	d := float64(0)
+
+	if 3 > len(points) {
+		return 0
+	}
+
+	for i := 0; i < len(points)-1; i++ {
+		h := points[i]
+		k := points[i+1]
+		u := h[0] * c * math.Cos(h[1]*Hq)
+
+		hhh := h[1] * c
+		v := k[0] * c * math.Cos(k[1]*Hq)
+		d = d + (u*k[1]*c - v*hhh)
+	}
+
+	g1 := points[len(points)-1]
+	point := points[0]
+	eee := g1[0] * c * math.Cos(g1[1]*Hq)
+	g2 := g1[1] * c
+
+	k := point[0] * c * math.Cos(point[1]*Hq)
+	d += eee*point[1]*c - k*g2
+	return 0.5 * math.Abs(d) / float64(1000000)
+}