Add missing numbers of 0's and 1's in an array
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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].
1 Comment
Walter Roberson
on 26 Sep 2021
Edited: Walter Roberson
on 26 Sep 2021
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.
Answers (2)
Walter Roberson
on 26 Sep 2021
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])
zend = strfind([M 1], [0 1])
zlengths = zend - zstarts + 1
ostarts = strfind([0 M], [0 1])
oends = strfind([M 0], [1 0])
olengths = oends - ostarts + 1
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
elements = zeros(1,length(runs));
elements(2:2:end) = 1;
newM = repelem(elements, 1, runs);
num2str(newM)
0 Comments
Akira Agata
on 26 Sep 2021
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');
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