Question

是否有用于在Java中创建指定大小的单位矩阵的实用程序？

Answer 1

尝试Apache Commons Math for commonly used linear algebra：

// Set dimension to the size of the square matrix that you would like
// Example, this will make a 3x3 matrix with ones on the diagonal and
// zeros elsewhere.
int dimension = 3;
RealMatrix identity = RealMatrix.createRealIdentityMatrix(dimension);

Answer 2

如果您只想使用二维数组来表示矩阵而没有第三方库：

public class MatrixHelper {
  public static double[][] getIdentity(int size) {
    double[][] matrix = new double[size][size];
    for(int i = 0; i < size; i++) matrix[i][i] = 1;
    return matrix;
  }
}

Answer 3

我建议Jama满足您的所有矩阵需求。有人要求生成identity matrix（请参阅identity method）。

Answer 4

一种节省内存的解决方案是创建一个类似的类：

public class IdentityMatrix{
     private int dimension;

     public IdentityMatrix(int dimension){
          this.dimension=dimension
     }

     public double getValue(int row,int column){
          return row == column ? 1 : 0;
     }
}

如何在Java中创建任意大小的单位矩阵？

4 个答案: