Unless otherwise stated in the help messages, you cannot use files of data as input to my toolbox functions. You must first read the data into Matlab variables and then use the variables as input to the functions.
In the example you give, if n.txt, e.txt and u.txt are text files containing local geodetic north, east and up coordinates, respectively, try using the following:
lat=0.76; % radians
lon=0.36; % radians
Feel free to email me at email@example.com if you need further help using my toolbox.
22 Sep 2014
Toolbox for angle, coordinate and date conversions and transformations. Version 2.97.