OpenCV random forest CvRTrees error

Question

I got this error while using random forest inside OpenCV:

OpenCV Error: Bad argument (5273-th value of 220-th (ordered) variable (=-1.70141e+38) is too large) in CvDTreeTrainData::set_data, file /home/XXX/Downloads/opencv-2.4.6.1/modules/ml/src/tree.cpp, line 551
terminate called after throwing an instance of 'cv::Exception'
  what():  /home/XXX/Downloads/opencv-2.4.6.1/modules/ml/src/tree.cpp:551: error: (-5) 5273-th value of 220-th (ordered) variable (=-1.70141e+38) is too large in function CvDTreeTrainData::set_data

Aborted (core dumped)

It is strange because the printed number is not out of the float range (-3.4E+38 to +3.4E+38)

I found out where is printed in the source of opencv, but I'm not able to understand what's the problem:

the file is tree.cpp

for( i = 0; i < sample_count; i++ )
        {
            float val = ord_nan;
            int si = sidx ? sidx[i] : i;
            if( !mask || !mask[(size_t)si*m_step] )
            {
                if( idata )
                    val = (float)idata[(size_t)si*step];
                else
                    val = fdata[(size_t)si*step];

                if( fabs(val) >= ord_nan )
                {
                    sprintf( err, "%d-th value of %d-th (ordered) "
                        "variable (=%g) is too large", i, vi, val );
                    CV_ERROR( CV_StsBadArg, err );
                }
                num_valid++;
            }

            if (is_buf_16u)
                udst[i] = (unsigned short)i; // TODO: memory corruption may be here
            else
                idst[i] = i;
            _fdst[i] = val;

        }

Can anyone give me an hint?

Answer 1

If you check line 551 in the tree.cpp file you can see that fabs(val) >= ord_nan is required where ord_nan = FLT_MAX*0.5f. So it is fails when val == -1.70141e+38 since it is bigger than this limit.