Question

I have a double array in matlab whose elements are being output to a file in hexidecimal format. I want to output it with no decimal places and I can’t seem to figure out how to do this when the value being output is a negative number. I’ve tried:

    >> A = ones(1,4);
    >> fid = fopen('test.txt', 'r');
    >> value = A(2);
    >> fid = fopen('test.txt', 'w');
    >> fprintf(fid,'%x\r\n', value);
    >> fprintf(fid,'%.0x\r\n', value);
    >> value = -value;
    >> fprintf(fid,'%.0x\r\n', value);
    >> fprintf(fid,'%0.0x\r\n', value);
    >> fprintf(fid,'%0.0x\r\n', value);
    >> fprintf(fid,'%1.0x\r\n', value);
    >> fprintf(fid,'%x\r\n', value);

And the output file looks like:

    1
    1
    -1e+000
    -1e+000
    -1e+000
    -1e+000
    -1.000000e+000

I really just want it to be able to print out ‘-1’;

Sorry if this is obvious but its really hard to find this information as there are so many different formats.

Answer 1

Did you try changing value = -value; to value = round(-value);?

Alternatively, output absolute values only, but prepend ‘-‘ if the value is negative:

if value < 0, 
  fprintf('-%x', abs(value));
else
  fprintf('%x', abs(value));
end