'PathIn'

This argument is optional. It is a string that specifies the Path to the folder where the input files (as defined in your FileStruct ) are located.
If not specified, the files are searched in the current folder (displayed in Matlab)

Example:
('PathIn', '/lena13/home_users/users/datalinks/MYMANIP')
or
('PathIn','/lena13/home_users/users/datalinks/MYMANIP/')

The last slash is to be added if it is not specified in your FileStruct.