如何将数据表转换为c＃wpf中双精度的矩阵[] []？ [英] How do i convert a datatable to a matrix[][] of doubles in c# wpf?

问题描述

我正在尝试将dataTable转换为双精度矩阵[] []但没有成功。

我有一个dataTable，例如： 20列100行。我想将值从2列提取到最后一列，并将其存储到双精度矩阵[] []中。



我尝试了什么：

I'm trying to convert a dataTable to a matrix [][] of doubles with no success.
I have a dataTable with e.g. 20 columns and 100 rows. I want to extract the values from the 2 column to the last column and store this into a matrix[][] of doubles.

What I have tried:

public double[][] ConvertDataTableToMatrix(DataTable dt)
      {
          double[][] matrix = new double[dt.Rows.Count][];

          //start from second row as ColumnNames are stored in first row

          for (int row = 1; row < dt.Rows.Count + 1; row++)
          {
              for (int col = 1; col < dt.Columns.Count; col++)
              {
                  matrix[row] = Convert.ToDouble(dt.Rows[row - 1][col]);

              }
          }

         
          return matrix;
      }

推荐答案

尝试这样的事情：

Try something like this:

public double[][] ConvertDataTableToMatrix(DataTable dt)
{
    double[][] matrix = new double[dt.Rows.Count][];
    Converter<object, double> converter = Convert.ToDouble;
    
    for (int row = 0; row < dt.Rows.Count; row++)
    {
        matrix[row] = Array.ConvertAll(dt.Rows[row].ItemArray, converter);
    }
    
    return matrix;
}

DataRow.ItemArray属性（System.Data） [ ^ ]



编辑： ItemArray 返回对象的数组，需要将其转换为<$的数组C $ C>双。最简单的方法是使用 Array.ConvertAll 方法 [ ^ ]。



注意：您的代码中的注释不会感。你说你从第二行开始，但你的循环从 1 到 Rows.Count 包括在内，并且然后使用 row - 1 作为循环中的索引器。因此，您将遍历所有行，包括第一行。

DataRow.ItemArray Property (System.Data)[^]

ItemArray returns an array of object, which needs to be converted to an array of double. The easiest way to do that is to use the Array.ConvertAll method[^].

NB: The comment in your code makes no sense. You say you're starting from the second row, but your loop runs from 1 to Rows.Count inclusive, and you then use row - 1 as the indexer within the loop. As a result, you're looping over all of the rows, including the first one.

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