041f250f_lo__C___linear_algebra_library__auto_detect
Numerical data stored in machine dependent binary format, with a simple header to speed up loading. The header indicates the type of matrix as well as the number of rows and columns. For cubes, the header additionally specifies the number of slices. arma_binary is the default file_type for .save() and .quiet_save() [auto_detect] 
arma_binary
r a w _ a s c i i
r a w _ b i n a r y
a r m a _ a s c i i
a r m a _ b i n a r y
c s v _ a s c i i
h d f 5 _ b i n a r y
p g m _ b i n a r y
p p m _ b i n a r y
Armadillo: C++ linear algebra library
auto_detect