n = 0b1000;
bitshift(n,-1)
ans = uint8
4
Similarly, if you shift the number 15 (binary: 1111) to the left by two digits, you get 60 (binary:
111100).
n = 0b1111;
bitshift(15,2)
ans = 60
When you shift the bits of a negative number, bitshift preserves the signed bit. For example, if you
shift the signed integer -3 (binary: 11111101) to the right by 2 digits, you get -1 (binary: 11111111).
In these cases, bitshift fills in on the left with 1s rather than 0s.
n = 0b11111101s8;
bitshift(n,-2)
ans = int8
-1
Writing Bits
You can use the bitset function to change the bits in a number. For example, change the first bit of
the number 8 to a 1 (which adds 1 to the number):
bitset(8,1)
ans = 9
By default, bitset flips bits to on or 1. You can optionally use the third input argument to specify the
bit value.
bitset does not change multiple bits at once, so you need to use a for loop to change multiple bits.
Therefore, the bits you change can be either consecutive or nonconsecutive. For example, change the
first two bits of the binary number 1000:
bits = [1 2];
c = 0b1000;
for k = 1:numel(bits)
c = bitset(c,bits(k));
end
dec2bin(c)
ans =
'1011'
Another common use of bitset is to convert a vector of binary digits into decimal format. For
example, use a loop to set the individual bits of the integer 11001101.
data = [1 1 0 0 1 1 0 1];
n = length(data);
dec = 0b0u8;
for k = 1:n
dec = bitset(dec,n+1-k,data(k));
Bit-Wise Operations
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