Package NumericalIO



It might be useful ...

1) ... to rewrite function read_list and others for reading list (array, 
matrix) of expressions (not only of numbers).

write_data(
   matrix([2/5,3/7,-1/2],[0.5,-1.247,12.57]),
   "D:/Compmath/temp_matrix", comma
)$

- it works correctly

read_matrix("D:/Compmath/temp_matrix", comma);

- returns a rubbish

my_read_matrix(fn):=block([f,A,s],
     if (file_search(fn)=fn) then (
         f:openr(fn),
         A:matrix(),
         while (s:readline(f))#false do
             A:addrow(A,eval_string(concat("[",s,"]")))
     ),
     A
)$

my_read_matrix("D:/Compmath/temp_matrix");

- works correctly

2) ... to add some functions for write and read arbitrary text-file, for 
example:

(defun $fwrite (f &rest c)
     (with-open-file (stream f :direction :output)
         (loop for s in c
             do (write-line s stream))))

Usage:

fwrite("D:/Compmath/temp_file.txt",
     "a string",
     "another string",
     "again another string"
)$