MATLAB: How to convert signed decimal to binary

convertdecimal to binarytext file

i am converting signed decimal to binary reading value from file and after converting writing binary value in to file.here is my code but it gives me wrong answer
%
fid = fopen('dec_bin.txt','r');
fid1=fopen('dec_bin_con.txt','w');
tline = fgetl(fid);
while ischar(tline)
disp(tline);
abstline=abs(tline);
if abstline==tline
out_1a=dec2bin(tline,8);
else
out_1a=dec2bin(tline+256,8);
end;
disp(out_1a);
fprintf(fid1,'%s \n',out_1a);
fprintf(fid1,'\n');
tline = fgetl(fid);
end
fclose(fid);
fclose(fid1);
this is my dec_bin file:
0
-1
1
-2
2
-3
3
-4
4
and my output is:
00110000
0000110110100011
00110001
0000110110100110
00110010
0000110110100111
00110011
0000110110110010
00110100

Best Answer

fgetl() returns a string. You are doing conversion on the characters . If you want to do conversion on the values represented by those characters, you need to convert the strings to numeric form, such as with str2double()