bitget function working explanation needed

Question

Manu Chaudhary 2022-1-15

回答： Steven Lord 2022-1-15

I am completely new to matlab. I am really not able to understand bitget.

The sample code given on the matlab website is:

a1 = intmax('int8');
a2 = intmax('uint8');
b1 = bitget(a1,8:-1:1)

This code is giving me output as

b1 =

1×8 int8 row vector

0 1 1 1 1 1 1 1

Even after seeing the output, I am not being able to interpret the working of bitget. It would be great if someone can explain me this.

Answer 1

Steven Lord 2022-1-15

Here's an unsigned 8-bit integer.

x = 0b10011010u8 % x is 10011010
x = uint8
    154

The lowest order bit of x is 0. This makes sense since x is even.

bitget(x, 1)
ans = uint8
    0

The next three highest order bits (bits 4, 3, and 2) are 1, 0, and 1 respectively.

bitget(x, [4 3 2])
ans = 1×3
   1   0   1

Here are all the bits.

bitget(x, 8:-1:1) % x's binary representation is 10011010
ans = 1×8
   1   0   0   1   1   0   1   0