how to swap two bits in matlab.? which cammond is used for this..?

Input: n = 28, p1 = 0, p2 = 3

Output: 21

28 in binary is 11100. If we swap 0'th and 3rd digits,

we get 10101 which is 21 in decimal.

Answer 1

[KALYAN ACHARJYA]

>> a=de2bi(28)
a =
     0     0     1     1     1

Here swap first and Fifth Elements (Change as per your requirements)

>> a([1 5])=a([5 1])
a =
     1     0     1     1     0
>> a=bi2de(a)
a =
    13
>> 

[Sultan Mehmood]

how to apply 2 by 2 matrix.?

[Sultan Mehmood]

A=[21 28 54;25 27 54;29 21 76];

d=de2bi(A)

k=1:9;

L=[2,8,3,5,5,3,2,3,7];

P=[5,6,7,7,1,8,2,2,2];

d([L(k) P(k)]) = d([P(k) L(k)]);

B = bi2de(d);

Answer 2

[Chirag Nighut]

Remember that Matlab has 1 based indexing and therfore when you wish to swap the 0th and 3rd bit in above number, it is actually bit number 1 and 4.

Following code should work:

p1 = 1;
p2 = 4;
A = 28;
d = de2bi(A);
d([p1 p2]) = d([p2 p1]);
B = bi2de(d)

[Sultan Mehmood]

A=[21 28 54;25 27 54;29 21 76];

L=[2,8,3,5,5,3,2,3,7];

P=[5,6,7,7,1,8,2,2,2];

how we apply on this.