de2bi not working for large decimal number

I have a problem with de2bi. Just typing de2bi(bi2de(ones(1,56))) I should trivially obtain ones(1,56), but I obtain a row of 56 zeros and a one. Why is that?

Answer 1

[Stephen23]

"Why is that?"

Because those functions use double class, and your value is well above flintmax:

>> 2^53 % flintmax
ans = 9.0072e+015
>> bi2de(ones(1,56)) % your value
ans = 7.2058e+016

See also:

https://www.mathworks.com/matlabcentral/answers/76623-maximum-decimal-and-binary-values