计算2D-Array中的列总和

Question

我想计算2D数组每列的总和。 到目前为止我得到了这个：

public static double[] colMean(double[][] array){
    double arrayCopy[] = new double[array.length];

    for(int i = 0; i < array.length; i++ ){
        double colSum = 0;
        for(int k = 0; k < array.length ; k++){
            colSum = colSum + array[k][i];
        }       
        arrayCopy[i] = colSum; 
    }
    return arrayCopy; 
}

Answer 1

你在2d数组中循环如下：

for(int i = 0; i < array.length; i++ ){
        double colSum = 0;
        for(int k = 0; k < array[i].length ; k++){
            colSum = colSum + array[i][k];
        }

Answer 2

//Create a destination array to store column sums
//I'm supposing every row has the same number of columns
for (int i=0; i<array[0].length; i++) {
    destination_array[i]=0;
}

//Traversing the 2D array
for (int i=0;i<array.length; i++) {

    //Adding each column value at the column accumulator
    for (int k=0;k<array[i].length;k++ {
      destination_array[k]+=array[i][k];
    }
}

希望有所帮助