>> str = '2B.3A';
>> out = sscanf(str,'%lx.'); % use NUMEL(OUT) to detect integer or fractional
>> dcp = numel(str)-strfind(str,'.');
>> out = out(1) + out(2) ./ pow2(4*dcp)
out =
43.2265625
A more challenging example:
>> str = '3.243F6A8885A2F7A'; % π
>> out = sscanf(str,'%lx.');
>> dcp = numel(str)-strfind(str,'.');
>> out = out(1) + out(2) ./ pow2(4*dcp)
out =
3.14159265358979
Note that more than 16 integer digits or 16 fractional digits will not be correctly parsed by this method, and the output precision is limited by the double type anyway.
For the reverse conversion the usual method is:
- scale the fractional part by 16,
- convert the integer part to hexadecimal,
- repeat from step one until you run out of digits or reach some precision limit.
You will find plenty of examples of this method on the internet.
Alternatively, if you don't mind a few trailing zeros, it can be done in one step:
>> num = 43.2265625;
>> str = sprintf('%X.%016X',fix(num),mod(num,1)*pow2(64))
str = 2B.3A00000000000000
Or a more challenging example:
>> num = pi
num = 3.141592653589793
>> str = sprintf('%X.%016X',fix(num),mod(num,1)*pow2(64))
str = 3.243F6A8885A30000
