How can i replace some elements of a matrix by oth

Question

I have a matrix consists of 1000 binary elements like below in Matlab:

M = 11001100101100001011010001001100101000101110010110001‌​10000101010110010111‌​0111001...

How i can split every 3 elements and replace them By another elements. for example 000 By 000000, 110 By 000001, 001 By 00001, 100 By 0001, 101 By 001, 010 By 01, 011 By 1.

I used this method but it doesn't work. What is wrong with it?

  Lookup_In  = [  000      110      001    100    101  010  011 ] ;
  Lookup_Out = {'000000','000001','00001','0001','101','01','1' } ;
  StrOut = repmat({'Unknown'},size(M)) ;
  [tf, idx] =ismember(M, Lookup_In) ;
  StrOut(tf) = Lookup_Out(idx(tf))

Answer 1

M here is randomly generated with 1000 binary elements:

rng(1);
M = randi([0 1], 1,1000);
fprintf('%d\n',M)

First, I zeropadded M to reach a length multiple of 3. Second, I reshaped the array in a matrix with 3 elements of each row and applied Lookup_Out.

c = mod(numel(M),3);
M = [M,zeros(1,3-c)]; %zeropadding to multiple of 3

M = reshape(M,[3,numel(M)/3])';

Lookup_In  = [  000      110      001    100    101  010  011 ] ;
Lookup_Out = {'000000','000001','00001','0001','101','01','1' } ;
StrOut = repmat({''},[1,size(M,1)]);

for r=1:size(M,1)
    StrOut{r} = Lookup_Out{str2double(sprintf('%d',M(r,:))) == Lookup_In};
end