我知道这个问题被回答过了,但我仍然无法与我的代码处理。 请有人指出我如何解决这个特定的代码。我想调用trace();但不知道在哪里调用新的跟踪。我尝试了不同的东西,但它对我不起作用。谢谢!非静态变量从静态内容调用java的
package matr;
import java.util.Scanner;
final public class Matrix {
private final int M;
private final int N;
private double[][] data;
public Matrix(int M, int N) {
this.M = M;
this.N = N;
data = new double[M][N];
}
public Matrix(double[][] data) {
M = data.length;
N = data[0].length;
this.data = new double[M][N];
for (int i = 0; i < M; i++)
for (int j = 0; j < N; j++)
this.data[i][j] = data[i][j];
}
private Matrix(Matrix A) {
this(A.data);
}
public static Matrix random(int M, int N, int r) {
Matrix A = new Matrix(M, N);
for (int i = 0; i < M; i++) {
for (int j = 0; j < N; j++) {
A.data[i][j] = (Math.random() * r);
}
}
return A;
}
public double trace() {
// trace a = new trace();
double t = 0;
for (int i = 0; i < Math.min(M, N); i++) {
t += data[i][i];
}
return t;
}
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("rows: ");
try {
int x = Math.abs(scan.nextInt());
System.out.println("columns: ");
int y = Math.abs(scan.nextInt());
System.out
.println("generate: ");
int r = scan.nextInt();
Matrix A = Matrix.random(x, y, r);
System.out.println("random A");
trace();
} catch (java.util.InputMismatchException e) {
System.out.println("Please enter a valid int");
}
}
}
我不反感,请解释“新跟踪”的含义。 trace()是一个方法,所以你不能创建它的一个实例。 – Sylar 2009-12-11 07:46:18