Question

I am trying to setup a C style multidimensional array. It is a 301 by 16 array of float values. I am using the following code :

float ** animationArray;

animationArray = (float **)calloc(16, sizeof(float*));
    for (int i=0; i<301; i++) {
        animationArray[i] = (float*)calloc(301, sizeof(float));
    }

    int i;

    for (i=0; i<301;i++) {

    NSArray * animationEntry = [Animations objectAtIndex:i];

    animationArray[i][0] = [[animationEntry objectAtIndex:0]doubleValue];
    animationArray[i][4] = [[animationEntry objectAtIndex:1]doubleValue];
    animationArray[i][8] = [[animationEntry objectAtIndex:2]doubleValue];
    animationArray[i][12] = [[animationEntry objectAtIndex:3]doubleValue];
    animationArray[i][1] = [[animationEntry objectAtIndex:4]doubleValue];
    animationArray[i][5] = [[animationEntry objectAtIndex:5]doubleValue];
    animationArray[i][9] = [[animationEntry objectAtIndex:6]doubleValue];
    animationArray[i][13] = [[animationEntry objectAtIndex:7]doubleValue];
    animationArray[i][2] = [[animationEntry objectAtIndex:8]doubleValue];
    animationArray[i][6] = [[animationEntry objectAtIndex:9]doubleValue];
    animationArray[i][10] = [[animationEntry objectAtIndex:10]doubleValue];
    animationArray[i][14] = [[animationEntry objectAtIndex:11]doubleValue];
    animationArray[i][3] = [[animationEntry objectAtIndex:12]doubleValue];
    animationArray[i][7] = [[animationEntry objectAtIndex:13]doubleValue];
    animationArray[i][11] = [[animationEntry objectAtIndex:14]doubleValue];
    animationArray[i][15] = [[animationEntry objectAtIndex:15]doubleValue];

    }

}

However this code causes a crash with the error “incorrect checksum for freed object – object was probably modified after being freed.”

Could anyone possibly spot what is wrong ?

Answer 1

You switched 16 and 301 in your for loop in regards to your allocation call.