Error in Mat CourtLinePixelDetector::filterLinePixels()

[DC-Cheng]

I meet error in Mat CourtLinePixelDetector::filterLinePixels(). any question or meaning about this function? It crashed on

        Mat l;
        eigen(t, l);
        if (l.at<float>(0,0) > 4* l.at<float>(0,1))
        {
          outputImage.at<uchar>(y,x) = GlobalParameters().fgValue;
        }