Read data file containing fractional numbers?

 On  May 22, 2011, Paul Bowyer wrote:
--------------------------------------------------

I modified it again like this to break out the various parts and add a 
close statement:
read_data1(%filename) := block([%s, %r],
   if not file_search(%filename) then
      (disp(" file not found "), return(false)),
   %s : openr(%filename),
   %r : [],
   while (l : readline(%s)) # false do
   (
    /*%r : cons(map(parse_string, split(l)), %r),*/
    %r : l,
    %r : split (%r),
    %r : parse_string ( %r ), /*chokes here. Need something different!*/
    disp( %r )
    /*reverse(%r)*/
   ),
   close(%s)
);

mydata1.dat contains (unquoted and without newlines in long expression, 
but with internal spaces):
10.3
14.4
read_data1(%filename):=block([%s,%r],if notfile_search(%filename) then 
(disp(" file not found "),return(false)) 
,%s:openr(%filename),%r:[],while (l:readline(%s))#false do 
%r:cons(map(parse_string,split(l)),%r),reverse(%r))
12.6
14.5

called as:
read_data1("/home/pfb/mydata1.dat");

and the output was:
parse_string: ["10.3"] is not a string.
#0: read_data1(%filename=/home/pfb/mydata1.dat)
  -- an error. To debug this try: debugmode(true);

Paul
-----------------------------------

Hi Paul, and thanks for catching my dumb typos.

The following version of read_data1 works with all data files I have
tested, decimal numbers, fractional numbers, and doesn't care
about text file line endings.

read_data1(%filename) := block ([%s,%r,%l],
    if not file_search (%filename) then
      (disp (" file not found "),return (false)),
      
    %s : openr (%filename),
    %r : [],
    
    while (%l : readline(%s)) # false do
            ( %r : cons (map(parse_string, split(%l)), %r)),
   close (%s), 
    
    reverse (%r))$


Ted