Command to pad zeros to specific locations in binary numbers?

Question

I need to pad zeros to specific locations in binary numbers. Looping the array form of a binary number such as dec2bin(43) and adding the zeros and adjusting th

Answer 1

Shai provided here bitshifting solution for a single binary number. I use it below to pad the zeros, the solution can probably made far faster -- currently being one of the slowest solution (some unnecessary dec2bin) or about the same speed as Jaheruddin's solution.

function out = bizarreBitShift( bNum, fromBit, shiftAmount )
    % construct a mask
    msk = uint32( (2^( fromBit - 1 ) )-1 ); 
    shiftPart = bitand( uint32(bNum), bitcmp(msk) ); % bitcmp - complement of bits
    staticPart = bitand( uint32(bNum), msk );
    out = bitshift( shiftPart , shiftAmount );
    out = bitor( out, staticPart );
end

function myOutput=shai(myInput,positions)
    shiftAmount=1;
    myOutput=sprintf('%d',myInput);
    myOutput=bin2dec(myOutput);
    k=0;
    for ii=1:length(positions)
        fromBit=positions(ii)+k;
        myOutput=bizarreBitShift(myOutput, fromBit, shiftAmount);
        k=k+1;
    end

    myOutput=ismember(dec2bin(myOutput),'1');
end

positions = [1 3 6]; %// example data
myInput = [1 0 1 0 1 1]; %// example data

sshai=@() shai(myInput,positions);
timeit(sshai)

Timing

ans =

   5.3288e-04