[SOLVED] gdb arithmetic exception - no division by zero

gdb arithmetic exception - no division by zero - runtime error

In order to get the mean value of a disparity map I had to write an own method to ignore negative disparity values:

float Utility::calcMeanDisparity(cv::Mat const& matrix)
{
  int total = 0;
  int numElements = 0;
  for(int r = 0; r < matrix.rows; ++r)
  {
    for(int c = 0; c < matrix.cols; ++c)
    {
      if(static_cast<float>(matrix.at<short>(r,c)) > 0)
      {
        total += static_cast<float>(matrix.at<short>(r,c));
        ++numElements;
      }
    }
  } 
  float mean = total / abs(numElements);
  std::cout << total << " / " << numElements << " = " << mean << std::endl;
  return mean;
}

but my code simply crashes after a certain time with the gdb error:

Program received signal SIGFPE, Arithmetic exception.
0x000000000044a992 in Utility::calcMeanDisparity (matrix=...) at src/utility.cpp:250
250   float mean = total / abs(numElements);

But there is no way that I am doing a division by zero. These are three of the last lines my code is trying to calculate:

950149 / 4275 = 222
804412 / 4429 = 181
873770 / 4253 = 205

I also added the abs(foo) stuff to be completely safe of divisions by zero.

Actually I do not have any idea what to do at the moment.

Maybe one of you guys has an idea for that.

Solution

Thanks to all the help, but the problem was easier than expected.

From time to time the disparity map contained areas with zero / negative values in it. so the whole submatrix I passed into the function had a mean of 0 this is why the if condition was ignored. So the final Division was 0 / 0 --> arithmetic exception.