out of range/not a number laser data

[mc13756]

I'm using the package with the above parameters to get line segments from laser data. I want to extract my lines as closer to the real length as possible, but the parameters I use don't correspond to the segment I get. I was playing with the parameters for a week and I found out that, maybe because of some reflections, some of the measurements return "nan" instead of a range number. How does the algorithm deals with this "nan" data? Is this why the segment in the image is shorter than the whole length of the measurements? Or maybe there is a better combination of parameters that solves the problem? Any help will be appreciated. Thanks in advance!