# MATLAB Function

1. Oct 21, 2012

### Hiche

1. The problem statement, all variables and given/known data

The problem asks us to write a MATLAB function that takes as input a vector 'v' representing a 64-bit machine number in double precision, and extract the sign (t), the exponent (c), and the mantissa (f).

2. Relevant equations

3. The attempt at a solution

I'm extremely novice at MATLAB and the instructor assigned us a HW and a tutorial without bothering to pass on lectures about the language so bear with me, please.

Code (Text):
function [t c f] = GetVector(v)
t = v(1);
c = v(2:12);
f = v(13:64);
end
Now, t will take the values 0 or 1 (the first element of the 64-bit representation), c will take the next 11 bits (the biased exponent), and f takes the remaining 52 bits. Now, my question is, do we have to subtract 1023 from the biased exponent to get e (the exponent) since they asked for the exponent? How exactly do we do that?

I think we have to create another function that converts the binary representation of c into decimal form then subtract 1023 from the 10-based number. If so, will this function do? And how exactly do functions return a value in MATLAB?

Code (Text):
function [dec] = Convert2to10(Ibase2)
for i = 1 : length(Ibase2)
dec = dec + str2num(Ibase2(i)) * 2^(length(Ibase2) - i);
end
end