bitget function is not invoking output bits in a vector

2018 11 26
3 个回答
回答已采纳
更新时间：2018 11 26
6 次查看（30 天）

0 个投票

k=k+1; %% k is counter and its chainging even more than (length(A))
for t = 1:1:length(A) %% A is a vector contains 8 elements
recovered_bits(1,k)= bitget(A(1,t),1); % extract LSB of each element in array and put them (LSB) in recovered_bits vector
k=k+1;
end
%% Output ----> recovered_bits = [] knowing that i trying to preallocate the vector previously

请先登录，再回答此问题。

 采纳的回答

madhan ravi
madhan ravi 2018-11-26
编辑：madhan ravi 2018-11-26

0 个投票

You don't need a counter for this case , please pre-allocate before loop!
recovered_bits=cell(1,length(A)); %proper pre-allocation
for t = 1:length(A)
recovered_bits{t}= bitget(A(1,t),1);
end
[recovered_bits{:}]

2 个评论
显示 无 隐藏 无

Anmar Mohammed
Anmar Mohammed 2018-11-26
编辑：Anmar Mohammed 2018-11-26
Thanks for sharing, it really helped, the k is needed simply because the code above is invoked in a bigger problem within functions, thank you all for helping me, greetings.
madhan ravi
madhan ravi 2018-11-26
Anytime :), see Steven Lords answer which is the efficient way to do what you are doing

请先登录，再进行评论。

更多回答（2 个）

Steven Lord
Steven Lord 2018-11-26

1 个投票

Why loop?
r = randi([0 intmax('int8')], 8, 1, 'int8');
recovered_bits = bitget(r, 1);
result = [r, recovered_bits, mod(r, 2)]
The second and third columns of result should be the same.

1 个评论
显示 -1更早的评论 隐藏 -1更早的评论

Anmar Mohammed
Anmar Mohammed 2018-11-26
编辑：Anmar Mohammed 2018-11-26
hi, am working on image steganography.. i used loop because i needed the first LSB or i may need the second or the third LSBs.. the output depend on other parameters with entire recieved image.. your code is intersting i tried to have the fist 3 LSBs using your modified code but an error ocured concerning input size, any suggestions are much preciated, thanks in advance.
r = randi([0 intmax('uint8')], 8, 1, 'uint8');
recovered_bits = bitget(r, 1:3,'uint8');
result = [r, recovered_bits]
Error using bitget
Inputs must have the same size.

请先登录，再进行评论。

KALYAN ACHARJYA
KALYAN ACHARJYA 2018-11-26
编辑：KALYAN ACHARJYA 2018-11-26

0 个投票

Initiallize k=1, otherwise K is not defined
k=1; %% k is counter and its chainging even more than (length(A))
for t = 1:1:length(A) %% A is a vector contains 8 elements
recovered_bits(1,k)= bitget(A(1,t),1); % extract LSB of each element in array and put them (LSB) in recovered_bits vector
k=k+1;
end

2 个评论
显示 无 隐藏 无

KALYAN ACHARJYA
KALYAN ACHARJYA 2018-11-26
编辑：KALYAN ACHARJYA 2018-11-26
For example I have choosen different A
A=[4 6 7 4 3 0 8 4];
for t=1:1:length(A) %% A is a vector contains 8 elements
recovered_bits(t)=bitget(A(1,t),1); % extract LSB of each element in array and put them (LSB) in recovered_bits vector
end
%% Output ----> recovered_bits = [] knowing that i trying to preallocate the vector previously
disp(recovered_bits);
Anmar Mohammed
Anmar Mohammed 2018-11-26
Oh.. am sorry it's already initialized and its K=1 not K=k+1 as wrote above, my bad.

请先登录，再进行评论。

类别

在 帮助中心 和 File Exchange 中查找有关 MATLAB 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by