在Java中的Vector2d类中旋转

public class Vector2D {
    // ...

    public void rotate(double radians) {
        // ...
    }
}

public class Vector2D {
    // ...

    public void rotate(double radians) {
        double[][] rotationMatrix = new double[2][2];
        double cos = Math.cos(radians);
        double sin = Math.sin(radians);
        rotationMatrix[0][0] = cos;
        rotationMatrix[0][1] = -sin;
        rotationMatrix[1][0] = sin;
        rotationMatrix[1][1] = cos;

        for (int i = 0; i < 2; i++) {
            for (int j = 0; j < 2; j++) {
                this.x = rotationMatrix[i][j] * this.x;
                this.y = rotationMatrix[i][j] * this.y;
            }
        }
    }
}

Vector2D vector = new Vector2D();
vector.setLocation(1, 0);
vector.rotate(Math.toRadians(45));