Convert floating point to binary
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Hiii...
I want to ask how to convert floating point to binary in MATLAB
Thank you
采纳的回答
Andrei Bobrov
2012-1-7
e.g.:
a = 1234.57849; % your float point number
n = 16; % number bits for integer part of your number
m = 20; % number bits for fraction part of your number
% binary number
d2b = [ fix(rem(fix(a)*pow2(-(n-1):0),2)), fix(rem( rem(a,1)*pow2(1:m),2))]; %
% the inverse transformation
b2d = d2b*pow2([n-1:-1:0 -(1:m)].');
EDIT [16:32(UTC+4) 08.01.2012]
a = 1234.57849; % your float point number
n = 16; % number bits for integer part of your number
m = 25; % number bits for fraction part of your number
% binary number
d2b = fix(rem(a*pow2(-(n-1):m),2));
% the inverse transformation
b2d = d2b*pow2(n-1:-1:-m).';
7 个评论
Walter Roberson
2012-1-7
Been a while since I saw a 36 bit word ;-)
(Yes, I have used 36 bit computers.)
Julien Cohen
2016-5-20
Much thanks (4 years later), this worked perfectly in my implementation of a genetic algorithm function.
OMID Fattemi
2017-2-10
for implementing GA, I used randint function to generate initial population as
d2b=randint(1,m+n);
then by the following code, decimal floating number is obtained:
b2d = d2b*pow2(n-1:-1:-m)';
Dave Amels
2020-3-20
DEC system 10
An Vo
2020-12-3
This code works perfectly for positive number. I run with negative number, the binary sequence contains bit 0, 1 and -1. bit -1 is not right. How can I fix this problem?
Walter Roberson
2020-12-3
As discussed below, for negative values, you need to be specific about which representation you want to use for the binary fraction.
saba h
2021-8-8
Thanks.
更多回答（5 个）
Oliver P
2016-8-10
1 个投票
Thank you for the cute and elegant solution! Unfortunately it's only working for positive floats. Negative floats will produce the same result as positive floats, but with negative bits. Which, of course, is not valid. And it's not the proper representation of negative values anyway.
5 个评论
Walter Roberson
2016-8-10
The proper representation of negative values? As decreed by which King?
I'm not aware of a king here, but an association called IEEE. :-) The IEEE 754 format defines, for example, the leading bit convention. Matlab converts -22.9 properly to binary32 when you use:
dec2bin(typecast(single(-22.9), 'uint32'))
It's also possible to convert to binary64 in a similar way. But not to custom formats. Please do check this webpage for more info on this topic: IEEE 754 Converter
Walter Roberson
2016-8-11
IEEE 754 defines one way to represent single precision numbers as binary, but it is far from being the only valid way.
When people ask about converting negative floating point to binary, the context is most typically the need to transmit quantized signals, which is almost always a fixed-point context, not a floating-point context. IEEE 754 does not deal with fixed point.
Oliver P
2016-8-12
Yes, I agree. As far as I'm aware Matlab uses IEEE-754 for all floating-point (single, double and custom) and for unsigned fixed-point calculations. Only for signed fixed-point it's using two's-complement representation.
Walter Roberson
2016-8-12
编辑：Walter Roberson
2017-2-10
The "Fixed Point Toolbox" can handle floating point numbers, but are only IEEE 754 if you request very specific formats.
I do not recall that the internal format for floating point number in the Symbolic Toolbox is documented.
The Fixed Point Toolbox offers Separated Sign. I would need to recheck to see if it offers One's Complement.
Walter Roberson
2012-1-7
0 个投票
You need to define the fraction representation in binary.
1 个评论
Walter Roberson
2020-12-3
naghma tabassum
2016-10-12
编辑：Walter Roberson
2016-10-12
0 个投票
Aneesh paulsagin
2018-3-16
编辑：Walter Roberson
2020-12-3
convert complex number to binary number
A = [-0.0040383664156692-0.00294191598222591i, ...
1.00279327279556+0.00768012699728154i, ...
-0.00226521017869135+0.00526418383309796i, ...
0.999498954084202-0.007158248828685i, ...
-0.00549315262581557+0.00808461388120792i, ...
0.998352426774419+0.00927983415466687i, ...
0.00736345881927219+0.00540426830690426i, ...
0.989408434745709-0.0144762821959683i, ...
0.00827899268722473+0.0122398877118786i, ...
0.999298739008971-0.0129949269950415i, ...
-5.47057549608037e-07-0.0130605748664198i, ...
1.01414402334238+0.0131228156923076i, ...
0.000678728159952879-0.00434397278237206i, ...
0.985341332736134+0.0239798712601118i, ...
0.0109818351271128-0.00658607972360998i, ...
1.01709879921672-0.00394256645505557i, ...
0.000335417716939878-0.00461609765687651i, ...
0.996785178287252-3.51718069407279e-05i, ...
-0.0137042758344959+0.00734580139566216i, ...
1.01389851161064+0.00526816880638668i, ...
-0.0143246406043654-0.0173541476823603i, ...
0.984838248467196-0.00274924075252472i, ...
-0.00383017735389232-0.00877400220581385i, ...
0.996013541706753+0.0113592028562242i, ...
-0.00607963966107746-0.00701052911751136i, ...
1.00401827238935-0.0163653626342944i]
4 个评论
Walter Roberson
2020-12-3
A_binary = reshape(dec2bin(typecast(reshape([real(A(:).'); imag(A(:).')], 1, []),'uint64'),64).',1, []);
format long g
A = [
1.01709879921672-0.00394256645505557i, ...
0.996013541706753+0.0113592028562242i, ...
-0.00607963966107746-0.00701052911751136i, ...
]
A_binary_out = reshape(dec2bin(typecast(reshape([real(A(:).'); imag(A(:).')], 1, []),'uint8'),8).',1, []);
tn = tempname(); %temporary file name
fid = fopen(tn, 'w');
fwrite(fid, A_binary_out, 'char');
fclose(fid);
fid = fopen(tn, 'r');
A_binary_in = char(fread(fid, [1 inf], 'uint8'));
fclose(fid);
pairs = typecast(uint8(bin2dec(reshape(A_binary_in, 8, []).')),'double');
A_reconstructed = pairs(1:2:end) + 1i .* pairs(2:2:end)
If your original A did not happen to be a column vector, then you will need a step to reshape it to the original size.
Ian Ono
2021-10-19
Great!
Much thanks
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