Finding the matrix logarithm.

Here’s an example of a Java program that calculates the matrix logarithm using the Apache Commons Math library:

  import org.apache.commons.math3.linear.MatrixUtils;

  import org.apache.commons.math3.linear.RealMatrix;

  public class MatrixLogarithmExample {

    public static void main(String[] args) {

        // Input matrix

        double[][] matrixData = {{1.0, 2.0}, {3.0, 4.0}};

        RealMatrix inputMatrix = MatrixUtils.createRealMatrix(matrixData);

        // Calculate the matrix logarithm

        RealMatrix logarithmMatrix = matrixLogarithm(inputMatrix);

        // Print the result

        System.out.println("Matrix Logarithm:");

        printMatrix(logarithmMatrix);
    }
    public static RealMatrix matrixLogarithm(RealMatrix matrix) {

        // Use Apache Commons Math library to calculate the matrix logarithm

        return MatrixUtils.log(matrix);
    }
    public static void printMatrix(RealMatrix matrix) {

        int rows = matrix.getRowDimension();

        int cols = matrix.getColumnDimension();

        for (int i = 0; i < rows; i++) {

            for (int j = 0; j < cols; j++) {

                System.out.printf("%.4f\t", matrix.getEntry(i, j));

            }

            System.out.println();

      }
    }
}

In this example, we use the Apache Commons Math library to perform the matrix logarithm calculation. The `matrixLogarithm` method takes a `RealMatrix` as input and returns the logarithm of the matrix. The `printMatrix` method is used to print the matrix elements in a formatted manner.

To run this code, you’ll need to have the Apache Commons Math library added to your project’s dependencies. You can download it from the Apache Commons Math website (https://commons.apache.org/proper/commons-math/).