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

조회 수: 29(최근 30일)
kamel attafkamel
kamel attafkamel 2021년 9월 26일 5:12
답변: Akira Agata 2021년 9월 26일 8:21
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].
  댓글 수: 1
Walter Roberson
Walter Roberson 2021년 9월 26일 6:06
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.

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답변(2개)

Walter Roberson
Walter Roberson 2021년 9월 26일 8:05
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'

Akira Agata
Akira Agata 2021년 9월 26일 8:21
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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