Add missing numbers of 0's and 1's in an array

hello, I have a sequence of 1's and o's values.

Example: I have an 1D array which looks like:

[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0]

What I want is to count elements connected to each other and if(mod(elements connected to each other ,10)>5 then add (10-mod) of 1's or 0's

the result can be something like this:

[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0].

[Walter Roberson]

Jan has a File Exchange contribution for Run Length Encoding.

Once you know the counts, it is easy to modify the counts in the data and then ask to do run length decoding.

Answer 1

[Walter Roberson]

M = [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0];
zstarts = strfind([1 M], [1 0])

zstarts = 1×2

1 24

zend = strfind([M 1], [0 1])

zend = 1×2

16 31

zlengths = zend - zstarts + 1

zlengths = 1×2

16 8

ostarts = strfind([0 M], [0 1])

ostarts = 17

oends = strfind([M 0], [1 0])

oends = 23

olengths = oends - ostarts + 1

olengths = 7

if zstarts(1) ~= 1; zlengths = [0 zlengths]; end
runs(1:2:length(zlengths)*2-1) = zlengths;
runs(2:2:length(olengths)*2) = olengths;

mods = mod(runs,10);
mask = mods > 5;
runs(mask) = ceil(runs(mask)/10)*10;
runs

runs = 1×3

20 10 10

elements = zeros(1,length(runs));
elements(2:2:end) = 1;
newM = repelem(elements, 1, runs);
num2str(newM)

ans = '0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  1  1  1  1  1  1  1  1  1  0  0  0  0  0  0  0  0  0  0'

Answer 2

[Akira Agata]

How about the following?

% Sample data
x = [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0];

% Calculate run-length for each element
idx = diff(x) ~= 0;
idx = [true,idx];
g = cumsum(idx);
group = g(idx)';
element = x(idx)';
lengthIn = accumarray(g',1);

% if mod(length,10)>5, add(10-mod(...))
lengthOut = lengthIn;
idx = mod(lengthIn,10) > 5;
lengthOut(idx) = lengthOut(idx) + (10-mod(lengthIn(idx),10));

% Summarize the result
tSummary = table(group,element,lengthIn,lengthOut);

% >> tSummary
% tSummary =
%  3×4 table
%    group    element    lengthIn    lengthOut
%    _____    _______    ________    _________
%      1         0          16          20    
%      2         1           7          10    
%      3         0           8          10

% Then, create the output based on the tSummary
c = arrayfun(@(ele,len)repelem(ele,1,len), tSummary.element, tSummary.lengthOut,...
    'UniformOutput', false)
x2 = cell2mat(c');