input: Numerical data stored in raw ASCII format, without a header. The numbers are separated by whitespace. The number of columns must be the same in each row. Cubes are loaded as one slice. Data which was saved in Matlab/Octave using the -ascii option can be read in Armadillo, except for complex numbers. Complex numbers are stored in standard C++ notation, which is a tuple surrounded by brackets: eg. (1.23,4.56) indicates 1.24 + 4.56i. [auto_detect] 
output: raw_ascii
options: r a w _ a s c i i
options: r a w _ b i n a r y
options: a r m a _ a s c i i
options: a r m a _ b i n a r y
options: c s v _ a s c i i
options: h d f 5 _ b i n a r y
options: p g m _ b i n a r y
options: p p m _ b i n a r y