Binary to floating point representation using IEEE-754

Question

Arslan Ahmad 2018-2-22

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/384157-binary-to-floating-point-representation-using-ieee-754

评论： Anton Shishkin 2022-9-12

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

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Arslan Ahmad 2018-2-22

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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Answer 1

Stephen23 2018-2-22

2
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https://ww2.mathworks.cn/matlabcentral/answers/384157-binary-to-floating-point-representation-using-ieee-754#answer_306477

编辑：Stephen23 2018-2-22

在 MATLAB Online 中打开

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

See also https://en.wikipedia.org/wiki/Single-precision_floating-point_format

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Arslan Ahmad 2018-2-22

Thanks a lot

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Answer 2

James Tursa 2018-2-22

4
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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/384157-binary-to-floating-point-representation-using-ieee-754#answer_306554

编辑：James Tursa 2018-2-22

在 MATLAB Online 中打开

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.