(是的,我知道bojc在技术上只是C。但我的意思是,我用信息和其他东西写了它。我只有java背景,不太了解普通的C),但是它跑得非常慢。所以我写了(我所想的)代码是相同的代码,但现在这组环形的代码产生了不同的值(只对其中的一些数字),而现在我无法在我生命中找出不同的值。我正在做的是循环10次,在母体之间做1次倍数和1次加1次。我希望具有两种语言背景的人能够挑出我错误转出的代码部分。我没有事先为任何一个阵列(那些是硬码和未受到影响的)改变任何东西,所以A1,A2,等等在代码的两部分都有相同的值。

C 中的当前代码 :

    for (int m = 0; m < 10; m++) {

    //Do matrix multiplication between A1 and A2.  Store in temporary B1
    for( int i = 0; i < 13; i++ )
        for( int j = 0; j < 43; j++ ) {
            double tempTotal = 0;
            for( int k = 0; k < 43; k++){
                tempTotal = tempTotal + A1[i][k] * A2[k][j];
            }
            B1[i][j] = tempTotal;
        }

    //Assign B1 data back into A1 after the multiplication is finished
    for(int i = 0; i < 13; i++)
        for(int j = 0; j<43; j++)
            A1[i][j] = B1[i][j];

    //Add C1 and A1.  Store into C1.
    for (int l = 0; l < 13; l++) 
        for (int n = 0; n < 43; n++) 
            C1[l][n] = C1[l][n] + A1[l][n];

}//end m for loop

这是旧的ObjC代码:

 for (int m = 0; m < 10; m++) {
    //multiply A1 and A2.  Store into A1
    A1 = [LCA_Computation multiply:A1 withArray:A2];    //LCA_Computation is the name of the .m class file in which this all happens.  

    //Add C1 and A1.  Store into C1
    for (int i = 0; i < 13; i++) 
        for (int j = 0; j < 43; j++) 
            [[C1 objectAtIndex:i] replaceObjectAtIndex:j withObject:[NSNumber numberWithDouble: [[[C1 objectAtIndex: i] objectAtIndex: j] doubleValue] + [[[A1 objectAtIndex: i] objectAtIndex: j] doubleValue]]];

}//end m for loop

//multiply method
   + (NSMutableArray*)multiply:(NSMutableArray*)a1 withArray:(NSMutableArray*)a2
{
    int a1_rowNum = [a1 count];
    int a2_rowNum = [a2 count];
    int a2_colNum = [[a2 objectAtIndex:0] count];
    NSMutableArray *result = [NSMutableArray arrayWithCapacity:a1_rowNum];
    for (int i = 0; i < a1_rowNum; i++) {
        NSMutableArray *tempRow = [NSMutableArray arrayWithCapacity:a2_colNum];
        for (int j = 0; j < a2_colNum; j++) {
            double tempTotal = 0;
            for (int k = 0; k < a2_rowNum; k++) {
                double temp1 = [[[a1 objectAtIndex:i] objectAtIndex:k] doubleValue];
                double temp2 = [[[a2 objectAtIndex:k] objectAtIndex:j] doubleValue];
                tempTotal += temp1 * temp2;
            }
            //the String format is intentional.  I convert them all to strings later.  I just put it in the method here where as it is done later in the C code
            [tempRow addObject:[NSString stringWithFormat:@"%f",tempTotal]];
        }
        [result addObject:tempRow];
    }
    return result;
}