无法使用SimpleMatrix静态引用非静态对象

Question

我想使用Kabsch算法（https://gist.github.com/JDevlieghere/7039971）的Java实现。我不明白如何为矩阵P和Q指定数据集。

我需要从文件中读取这些矩阵，并尝试了以下操作：

public class Kabsch {

/**
 * Data set P
 */
SimpleMatrix P;

/**
 * Data set Q
 */
SimpleMatrix Q;

/**
 * Rotation matrix
 */
SimpleMatrix rotation;

/**
 * Translation matrix
 */
SimpleMatrix translation;

public static void main(String args[]) {

    try {
        String line1 = "";
        double[][] num = new double[50][50];
        int i = 0;
        int j = 0;

        BufferedReader file1 = new BufferedReader(new FileReader(new File("./file.txt")));
        while ((line1 = file1.readLine()) != null) {
            j = 0;
            StringTokenizer st1 = new StringTokenizer(line1, " ");
            while (st1.hasMoreTokens()) {
                num[i][j] = Double.parseDouble(st1.nextToken());
                j++;
            }
            i++;
        }
        file1.close();

        P = new SimpleMatrix(2,3,true,new double[]{num[0][0],num[0][1],num[0][2],num[1][0],num[1][1],num[1][2]});

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }


}

public Kabsch(SimpleMatrix P, SimpleMatrix Q) throws IllegalArgumentException {
    if(!isValidInputMatrix(P) || !isValidInputMatrix(Q))
        throw new IllegalArgumentException();
    if(P.numCols() != Q.numCols() || P.numRows() != Q.numRows())
        throw new IllegalArgumentException();
    this.P = P;
    this.Q = Q;
    calculate();
}

...

}

当我尝试从输入文件中将P设置为矩阵时，出现错误“无法对非静态字段P进行静态引用”。如何正确执行？