Python代码如下
- import pandas as pd
- # 读取数据
- data = pd.read_csv('data_row.csv')
- # 检查异常值
- def detect_outliers(data):
- outliers = []
- for col in data.columns:
- q1 = data[col].quantile(0.25)
- q3 = data[col].quantile(0.75)
- iqr = q3 - q1
- lower_bound = q1 - 1.5 * iqr
- upper_bound = q3 + 1.5 * iqr
- outliers.extend(data[(data[col] < lower_bound) | (data[col] > upper_bound)].index)
- return list(set(outliers))
- outliers = detect_outliers(data)
- print("异常数据数量:", len(outliers))
- # 处理异常值
- data.drop(outliers, inplace=True)
- # 保存清洗后的数据
- data.to_csv('clean_data_row.csv', index=False)
下面我们修改成C#代码
创建控制台程序,Nuget安装 CsvHelper 和 pythonnet

- public class Program
- {
- const string PathToPythonDir = "D:\\Python311";
- const string DllOfPython = "python311.dll";
- static void Main(string[] args)
- {
- // 数据清洗
- CleanData();
- }
- /// <summary>
- /// 数据清洗
- /// </summary>
- static void CleanData()
- {
- var originDatas = ReadCsvWithCsvHelper("data_row.csv");
- var outliers = DetectOutliers(originDatas);
- var outlierHashset = new HashSet<int>(outliers);
- // 清洗过后的数据
- var cleanDatas = originDatas.Where((r, index) => !outlierHashset.Contains(index)).ToList();
- try
- {
- Runtime.PythonDLL = Path.Combine(PathToPythonDir, DllOfPython);
- PythonEngine.Initialize();
- using (Py.GIL())
- {
- dynamic pd = Py.Import("pandas");
- dynamic np = Py.Import("numpy");
- dynamic plt = Py.Import("matplotlib.pyplot");
- dynamic fft = Py.Import("scipy.fftpack");
- dynamic oData = np.array(originDatas.ToArray());
- int oDataLength = oData.__len__();
- dynamic data = np.array(cleanDatas.ToArray());
- int dataLength = data.__len__();
- // 绘制原始数据图和清洗后数据图
- plt.figure(figsize: new dynamic[] { 12, 6 });
- // 原始数据图
- plt.subplot(1, 2, 1);
- plt.plot(np.arange(oDataLength), oData);
- plt.title("Original Datas");
- // 清洗后数据图
- plt.subplot(1, 2, 2);
- plt.plot(np.arange(dataLength), data);
- plt.title("Clean Datas");
- // 布局调整,防止重叠
- plt.tight_layout();
- // 显示图表
- plt.show();
- }
- }
- catch (Exception e)
- {
- Console.WriteLine("报错了:" + e.Message + "\r\n" + e.StackTrace);
- }
- }
- /// <summary>
- /// 检测异常值
- /// </summary>
- /// <param name="datas">原始数据集合</param>
- /// <returns>返回异常值在集合中的索引</returns>
- static List<int> DetectOutliers(List<double[]> datas)
- {
- List<int> outliers = new List<int>();
- var first = datas.First();
- for (int i = 0; i < first.Length; i++)
- {
- var values = datas.AsEnumerable().Select((row, index) => Tuple.Create(row[i], index)).ToArray();
- double q1 = Enumerable.OrderBy(values, x => x.Item1).ElementAt((int)(values.Length * 0.25)).Item1;
- double q3 = Enumerable.OrderBy(values, x => x.Item1).ElementAt((int)(values.Length * 0.75)).Item1;
- double iqr = q3 - q1;
- double lowerBound = q1 - 1.5 * iqr;
- double upperBound = q3 + 1.5 * iqr;
- outliers.AddRange(values.AsEnumerable()
- .Where(row => row.Item1 < lowerBound || row.Item1 > upperBound)
- .Select(row => row.Item2));
- }
- return outliers.Distinct().ToList();
- }
- /// <summary>
- /// 读取CSV数据
- /// </summary>
- /// <param name="filePath">文件路径</param>
- /// <returns>文件中数据集合,都是double类型</returns>
- static List<double[]> ReadCsvWithCsvHelper(string filePath)
- {
- using (var reader = new StreamReader(filePath))
- using (var csv = new CsvReader(reader, CultureInfo.InvariantCulture))
- {
- var result = new List<double[]>();
- // 如果你的CSV文件有标题行,可以调用ReadHeader来读取它们
- csv.Read();
- csv.ReadHeader();
- while (csv.Read())
- {
- result.Add(new double[] {
- csv.GetField<double>(0),
- csv.GetField<double>(1),
- csv.GetField<double>(2),
- });
- }
- return result;
- }
- }
- }
以下是运行后结果,左边是原始数据折线图,右边是清洗后数据折线图

源代码:https://gitee.com/Karl_Albright/csharp-demo/tree/master/PythonnetDemo/PythonnetClearData
抽稀算法
- def down_sampling(sig,factor=2, axis=0):
- '''
- 降采样
- Inputs:
- sig --- numpy array, 信号数据数组
- factor --- int, 降采样倍率
- axis --- int, 沿着哪个轴进行降采样
- '''
- Temp=[':']*sig.ndim
- Temp[axis]='::'+str(factor)
- return eval('sig['+','.join(Temp)+']')
- /// <summary>
- /// 降采样,其实就是抽稀算法
- /// </summary>
- static List<double[]> DownSampling(int factor = 2, int axis = 0)
- {
- if (axis != 0 && axis != 1)
- throw new ArgumentException("Axis must be 0 or 1 for a 2D array.");
- var datas = ReadCsvWithCsvHelper("clean_data_row3.csv");
- int dim0 = datas.Count;
- var first = datas.First();
- int dim1 = first.Length;
- var result = new List<double[]>();
- if (axis == 0)
- {
- var xAxis = dim0 / factor;
- var yAxis = dim1;
- for (int i = 0; i < xAxis; i++)
- {
- result.Add(datas[i * factor]);
- }
- }
- else if (axis == 1)
- {
- var xAxis = dim0;
- var yAxis = dim1 / factor;
- var item = new double[yAxis];
- for (int i = 0; i < xAxis; i++)
- {
- var deviceData = datas[i];
- for (int j = 0; j < yAxis; j++)
- {
- item[j] = deviceData[j * factor];
- }
- result.Add(item);
- }
- }
- return result;
- }
源代码:https://gitee.com/Karl_Albright/csharp-demo/tree/master/PythonnetDemo/PythonnetClearData