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Binary to floating point representation using IEEE-754

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I am given a Character array of length 32 made of only zeros and ones and i want to convert in floating point representation using IEEE-754. Can any one help???? My string is '10101110101101011010010110101001'. and my code uptill now is
sign=binary(1);
exp=binary(2:9);
mantissa=binary(10:32)
subt=bin2dec(exp);
e=-127+subt;
num=0;
for i=1:length(mantissa)
num=mantissa(i)*2^(-i)+num;
end
  1 Comment
Arslan Ahmad
Arslan Ahmad on 22 Feb 2018
i did it at last
function [result] = mySingle2Decimal(binary)
sign=str2num(binary(1));
exp=binary(2:9);
mant=binary(10:32);
subt=bin2dec(exp);
e=-127+subt;
num=0;
for i=1:length(mant)
num=str2num(mant(i))*2^(-i)+num;
end
result=(-1)^sign*(1+num)*2^(e);

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Accepted Answer

Stephen23
Stephen23 on 22 Feb 2018
Edited: Stephen23 on 22 Feb 2018
It is simple to avoid the loop:
S = '10101110101101011010010110101001';
%S = '00111110001000000000000000000000'; % Wikipedia example
V = S-'0'; % convert to numeric
frc = 1+sum(V(10:32).*2.^(-1:-1:-23))
pow = sum(V(2:9).*2.^(7:-1:0))-127
sgn = (-1)^V(1)
val = sgn * frc * 2^pow

More Answers (1)

James Tursa
James Tursa on 22 Feb 2018
Edited: James Tursa on 22 Feb 2018
Any method you choose is going to have to make assumptions about bit/byte ordering and the handling of the special inf, nan, and denormalized bit patterns. The following method simply assumes that the char array bit pattern you have matches the machine you are currently using and accounts for these special patterns:
result = typecast(uint32(bin2dec(S)),'single');
The other methods shown in this thread that work with the sign, exponent, and mantissa bits directly do not account for these special bit patterns.

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