Ltm 'file' [-c=n1] [-r=n2]
Writes the lines of the matrices given in file in
seperate matrices. The default assumption is that
the resulting matrices should be square.
In case either option r or c are given, the matrices
are given as n2xn1 matrices, where n1*n2=#columns of the
matrices of file.
-c=n1: the matrices will have n1 columns.
-r=n2: the matrices will have n2 rows.
Note that this function does exactly the inverse of Mtl!