添加 简易版的线性拟合

Project.FLY.Misc/MISC/MyMath.cs

@@ -490,6 +490,7 @@ namespace Misc
             }
         }
 
+
         public static void Linest(IEnumerable<double> y, IEnumerable<double> x, out double a, out double b)
         {
             if (y.Count() != x.Count())
@@ -526,6 +527,39 @@ namespace Misc
             }
         }
 
+        public static void Linest(IEnumerable<double> y, out double a, out double b)
+        {
+            double sumX = 0;
+            double sumY = 0;
+            double sumX2 = 0;
+            double sumXY = 0;
+            int validCount = 0;
+
+            int index = 0;
+            foreach (double value in y)
+            {
+                if (!double.IsNaN(value))
+                {
+                    sumXY += value * index;
+                    sumX2 += index * index;
+                    sumX += index;
+                    sumY += value;
+                    validCount++;
+                }
+                index++;
+            }
+
+            if (validCount > 1)
+            {
+                a = (validCount * sumXY - sumX * sumY) / (validCount * sumX2 - sumX * sumX);
+                b = sumY / validCount - a * sumX / validCount;
+            }
+            else
+            {
+                a = 1;
+                b = 0;
+            }
+        }
 
         /// <summary>
         /// 对环形数据 分区移位