From c97331d8eca8f9ef6a0c18ffce3518578b5638ff Mon Sep 17 00:00:00 2001
From: lx <ex_lixiang17@cosl.com.cn>
Date: 星期五, 15 八月 2025 10:21:11 +0800
Subject: [PATCH] update cr/or fit line
---
ErrorAnalysis.Service/Utility.cs | 125 +++++++++++++++++++++++++++++++++++++++++
1 files changed, 125 insertions(+), 0 deletions(-)
diff --git a/ErrorAnalysis.Service/Utility.cs b/ErrorAnalysis.Service/Utility.cs
index 6c10062..e491bad 100644
--- a/ErrorAnalysis.Service/Utility.cs
+++ b/ErrorAnalysis.Service/Utility.cs
@@ -1,5 +1,6 @@
锘縰sing System;
using System.Collections.Generic;
+using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
@@ -23,5 +24,129 @@
double y = y0 + (value - x0) * (y1 - y0) / (x1 - x0);
return y;
}
+
+ public static (double slope, double intercept) FitLine(PointF[] points)
+ {
+ // 璁＄畻鍚勬眰鍜岄」
+ int n = points.Length;
+ double sumX = 0, sumY = 0, sumXY = 0, sumX2 = 0;
+
+ foreach (var p in points)
+ {
+ sumX += p.X;
+ sumY += p.Y;
+ sumXY += p.X * p.Y;
+ sumX2 += p.X * p.X;
+ }
+
+ // 璁＄畻鏂滅巼鍜屾埅璺�
+ double denominator = n * sumX2 - sumX * sumX;
+ if (Math.Abs(denominator) < 1e-10) // 閬垮厤闄や互0
+ throw new InvalidOperationException("鐐归泦杩囦簬闆嗕腑锛屾棤娉曟嫙鍚堢洿绾�");
+
+ double slope = (n * sumXY - sumX * sumY) / denominator;
+ double intercept = (sumY - slope * sumX) / n;
+
+ return (slope, intercept);
+ }
+
+ public static double GetLineValue(double x, double slope, double intercept) => slope * x + intercept;
+
+ public static (double a, double b, double c) FitParabola(PointF[] points)
+ {
+ if (points.Length < 3)
+ throw new ArgumentException("鑷冲皯闇�瑕�3涓偣杩涜鎶涚墿绾挎嫙鍚�");
+
+ // 1. 璁＄畻鍚勯」姹傚拰鍊糩1,6](@ref)
+ int n = points.Length;
+ double sx = 0, sy = 0, sx2 = 0, sx3 = 0, sx4 = 0, sxy = 0, sx2y = 0;
+
+ foreach (var p in points)
+ {
+ double x = p.X;
+ double y = p.Y;
+ double x2 = x * x;
+ double x3 = x2 * x;
+ double x4 = x2 * x2;
+
+ sx += x;
+ sy += y;
+ sx2 += x2;
+ sx3 += x3;
+ sx4 += x4;
+ sxy += x * y;
+ sx2y += x2 * y;
+ }
+
+ // 2. 鏋勫缓姝ｈ鏂圭▼鐭╅樀[1,6](@ref)
+ double[,] matrix = {
+ { sx4, sx3, sx2, sx2y },
+ { sx3, sx2, sx, sxy },
+ { sx2, sx, n, sy }
+ };
+
+ // 3. 浣跨敤楂樻柉娑堝厓娉曟眰瑙�
+ double[] coefficients = GaussElimination(matrix);
+
+ return (coefficients[0], coefficients[1], coefficients[2]);
+ }
+
+ // 楂樻柉娑堝厓娉曞疄鐜帮紙甯﹂儴鍒嗕富鍏冮�夋嫨锛�
+ private static double[] GaussElimination(double[,] matrix)
+ {
+ int n = matrix.GetLength(0);
+ double[] result = new double[n];
+
+ // 鍓嶅悜娑堝厓
+ for (int i = 0; i < n - 1; i++)
+ {
+ // 閮ㄥ垎涓诲厓閫夋嫨
+ int maxRow = i;
+ for (int k = i + 1; k < n; k++)
+ {
+ if (Math.Abs(matrix[k, i]) > Math.Abs(matrix[maxRow, i]))
+ maxRow = k;
+ }
+
+ // 琛屼氦鎹�
+ if (maxRow != i)
+ {
+ for (int j = 0; j <= n; j++)
+ {
+ double temp = matrix[i, j];
+ matrix[i, j] = matrix[maxRow, j];
+ matrix[maxRow, j] = temp;
+ }
+ }
+
+ // 娑堝厓杩囩▼
+ for (int k = i + 1; k < n; k++)
+ {
+ double factor = matrix[k, i] / matrix[i, i];
+ for (int j = i; j <= n; j++)
+ {
+ matrix[k, j] -= factor * matrix[i, j];
+ }
+ }
+ }
+
+ // 鍥炰唬姹傝В
+ for (int i = n - 1; i >= 0; i--)
+ {
+ result[i] = matrix[i, n];
+ for (int j = i + 1; j < n; j++)
+ {
+ result[i] -= matrix[i, j] * result[j];
+ }
+ result[i] /= matrix[i, i];
+ }
+
+ return result;
+ }
+
+ public static double GetParabolaValue(double x, double a, double b, double c)
+ {
+ return a * x * x + b * x + c;
+ }
}
}
--
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