How to extract the 4 MSBs of decimal numbers in a matrix?

Hello everyone,

I would like to know if there is an elegant and easy way to get the 4 MSBs (or 4 LSBs) of decimal numbers in a 2D matrix?

Let's assume that all decimals in the matrix can be represented by 8-bit binary numbers. ([0-255])

I know i can use bitget() function to get the highest 4 bits (4 MSBs) by scanning all elements in the matrix.

For example:

A=[103 12; 250 125];
for i=1:4
    bitget(A(i),8:-1:5)
end

A simple code like above can be used to find the highest four bits of all elements in matrix A. However, im just wondering if there is another more efficient method.

Maybe converting A into a binary matrix and then getting the highest 4 bits can be a solution. But Im not quite sure how to do it in an efficient manner.

reshape( dec2bin(A',8)'-'0', [], size(A,1))';
%% how to get the 4 MSBs (or LSBs)?

Thanks,

Answer 1

[David Hill]

a=randi(255,10);
d=dec2bin(a(:),8);
msb4=d(:,1:4)-'0';