[Help-gsl] Doubt (bug?) in gsl_fit_linear function

[Ruchin Kansal]

Hi,

I am using gsl_fit_linear to fit a straight line through my data samples. 
Incidentally, I came across a situation when 
the data samples lie on a vertical line. I observed that in this case 
gsl_fit_linear returns everything as (nan). Is it a known behavior or there may 
be something wrong at my end?

I passed the following data samples to this function:
{(50, 52), (50, 50), (50, 53), (50, 49), (50, 51)}

Please help.

Regards,
Ruchin.