%sample program to read and write binary files

clear all;

%produce an array to write out

foo = rand(5,5);


%write out file using float32 type with no skip and forced little-endian
%output
fid = fopen('binary_write_1.txt','w');
fwrite(fid,foo,'float32',0,'l');
fclose(fid);

%write out array of 8-bit integers using big-endian ordering
foo = round(foo);
fid = fopen('binary_write_2.txt','w');
fwrite(fid,foo,'int8',0,'b');
fclose(fid);


%now read in the above files
fid = fopen('binary_write_1.txt','r');
bar = fread(fid);
size(bar)
%fread defaults to uint8, or an 8-bit unsigned integer
%thus the file is read incorrectly here to 100 8-bit values, rather than 25
%32-bit floating point values

%try reading file into shaped array, rather than a vector
%clear variable bar from before
clear bar;

%can reset file pointer from fread without closing and reopeing file using
%frewind or fseek
frewind(fid);

%read file
bar = fread(fid,[5 5],'float32',0,'l');
fclose(fid);

%try reading using wrong byte ordering
fid = fopen('binary_write_2.txt','r');
bar = fread(fid,[5 5], 'int8',0,'b');
%if you look at the original input array and bar, they are different

%try using correct byte ordering
frewind(fid);
bar = fread(fid, [5 5], 'int8',0','l');