矩陣相互覆蓋

我試圖根據某些條件在3個不同的矩陣中改變（乘以int）某個位置（i，j）的值。然而，當我打印整個矩陣似乎它乘以所有整數的第一個（甚至是那些第二和第三矩陣矩陣相互覆蓋

下面我宣佈全球矩陣和屬性，包括一些內存分配。

int HEIGHT; 
int WIDTH; 
int ** matrixR= new int*[HEIGHT]; 
int ** matrixG= new int*[HEIGHT]; 
int ** matrixB= new int*[HEIGHT];

然後，在功能予完成矩陣：

for(i=0; i<HEIGHT; i++){ 
     matrixR[i]= new int[WIDTH]; 
     matrixG[i]= new int[WIDTH]; 
     matrixB[i]= new int[WIDTH]; 
}

這裏是我評估每個矩陣的條件：

for (int i = 0; i < HEIGHT; ++i) { 
    for (int j = 0; j < WIDTH; ++j) { 
     float suma = pow(i - centerY, 2) + pow(j - centerX, 2); 
     if (suma > pow(radius, 2)) { 
      matrixR[i][j] = matrixR[i][j] * 1; 
     } 
    } 

} 

for (int i = 0; i < HEIGHT; ++i) { 
    for (int j = 0; j < WIDTH; ++j) { 
     float suma = pow(i - centerY, 2) + pow(j - centerX, 2); 
     if (suma > pow(radius, 2)) { 
      matrixG[i][j] = matrixG[i][j] * 2; 
     } 
    } 
} 

for (int i = 0; i < HEIGHT; ++i) { 
    for (int j = 0; j < WIDTH; ++j) { 
     float suma = pow(i - centerY, 2) + pow(j - centerX, 2); 
     if (suma > pow(radius, 2)) { 
      matrixB[i][j] = matrixB[i][j] * 3; 
     } 
    } 
}

然後，當我打印第一矩陣的元素：

for (int k = 0; k < HEIGHT; ++k) { 
    for (int i = 0; i < WIDTH; ++i) { 
     cout << matrixR[k][i] << " | "; 
    } 
    cout << '\n'; 
}

在那裏我應該得到matrixR[i][j]*1我越來越matrixB[i][j]。矩陣是否相互覆蓋？有什麼不對的嗎？

來源

2016-11-09 danielsto

Good writt恩問題。 :) – MordechayS

'matrixR [i] [j] = matrixR [i] [j] * 1;'？ –

你初始化矩陣中的值了嗎？ –

我爲centerX，centerY和radius添加了值，並添加了一個初始化部分（所有矩陣元素都是一個）。

我找不到一個錯誤，輸出爲

1 | 1 | 1 | 1 | 1 | 1 | 1 | 
1 | 1 | 1 | 1 | 1 | 1 | 1 | 
1 | 1 | 1 | 1 | 1 | 1 | 1 | 
1 | 1 | 1 | 1 | 1 | 1 | 1 | 
1 | 1 | 1 | 1 | 1 | 1 | 1 | 


2 | 2 | 2 | 2 | 2 | 2 | 2 | 
2 | 2 | 2 | 2 | 2 | 2 | 2 | 
2 | 2 | 2 | 1 | 2 | 2 | 2 | 
2 | 2 | 1 | 1 | 1 | 2 | 2 | 
2 | 2 | 2 | 1 | 2 | 2 | 2 | 


3 | 3 | 3 | 3 | 3 | 3 | 3 | 
3 | 3 | 3 | 3 | 3 | 3 | 3 | 
3 | 3 | 3 | 1 | 3 | 3 | 3 | 
3 | 3 | 1 | 1 | 1 | 3 | 3 | 
3 | 3 | 3 | 1 | 3 | 3 | 3 |

這是我使用的代碼：

// init variables 
int HEIGHT = 5; 
int WIDTH = 7; 
int centerY = 3; 
int centerX = 3; 
int radius = 1; 



int ** matrixR= new int*[HEIGHT]; 
int ** matrixG= new int*[HEIGHT]; 
int ** matrixB= new int*[HEIGHT]; 

for(int i=0; i<HEIGHT; i++){ 
     matrixR[i]= new int[WIDTH]; 
     matrixG[i]= new int[WIDTH]; 
     matrixB[i]= new int[WIDTH]; 
} 


// init matrix values 
{ 
for (int k = 0; k < HEIGHT; ++k) 
    for (int i = 0; i < WIDTH; ++i) 
     matrixR[k][i] = 1; 

for (int k = 0; k < HEIGHT; ++k) 
    for (int i = 0; i < WIDTH; ++i) 
     matrixG[k][i] = 1; 

for (int k = 0; k < HEIGHT; ++k) 
    for (int i = 0; i < WIDTH; ++i) 
     matrixB[k][i] = 1; 
} 


for (int i = 0; i < HEIGHT; ++i) { 
    for (int j = 0; j < HEIGHT; ++j) { 
     float suma = pow(static_cast<double>(i) - centerY, 2) + pow(static_cast<double>(j) - centerX, 2); 
     if (suma > pow(static_cast<double>(radius), 2)) { 
      matrixR[i][j] = matrixR[i][j] * 1; 
     } 
    } 

} 

for (int i = 0; i < HEIGHT; ++i) { 
    for (int j = 0; j < WIDTH; ++j) { 
     float suma = pow(static_cast<double>(i) - centerY, 2) + pow(static_cast<double>(j) - centerX, 2); 
     if (suma > pow(static_cast<double>(radius), 2)) { 
      matrixG[i][j] = matrixG[i][j] * 2; 
     } 
    } 
} 

for (int i = 0; i < HEIGHT; ++i) { 
    for (int j = 0; j < WIDTH; ++j) { 
     float suma = pow(static_cast<double>(i) - centerY, 2) + pow(static_cast<double>(j) - centerX, 2); 
     if (suma > pow(static_cast<double>(radius), 2)) { 
      matrixB[i][j] = matrixB[i][j] * 3; 
     } 
    } 
} 

for (int k = 0; k < HEIGHT; ++k) { 
    for (int i = 0; i < WIDTH; ++i) { 
     cout << matrixR[k][i] << " | "; 
    } 
    cout << '\n'; 
} 

cout << '\n'; 
cout << '\n'; 

for (int k = 0; k < HEIGHT; ++k) { 
    for (int i = 0; i < WIDTH; ++i) { 
     cout << matrixG[k][i] << " | "; 
    } 
    cout << '\n'; 
} 

cout << '\n'; 
cout << '\n'; 

for (int k = 0; k < HEIGHT; ++k) { 
    for (int i = 0; i < WIDTH; ++i) { 
     cout << matrixB[k][i] << " | "; 
    } 
    cout << '\n'; 
} 

std::cin.get();

來源

2016-11-09 14:52:10

謝謝，似乎是這是事實，我的矩陣是全球性的，我仍然不明白爲什麼它不會工作，但如果把（像你）放在一個main（）中，它可以工作。 – danielsto

你可以發佈你的原始代碼，哪裏出錯？ –

添加這使它編譯並運行：

for(int i=0; i < HEIGHT; ++i) { 
    for (int j=0; j < WIDTH; ++j){ 
     matrixR[i][j] = 3; 
     matrixG[i][j] = 20; 
     matrixB[i][j] = 30; 
    } 
} 

int centerX = 5; 
int centerY = 5; 
int radius = 2;

輸出我看起來很好...

來源

2016-11-09 14:54:45 Hal

矩陣相互覆蓋

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