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Writing the built in matlab function in simple code(like for loop, etc.)

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Jimmy cho
Jimmy cho on 23 Jan 2021
Edited: Adam Danz on 24 Jan 2021
Hi guys,
I'm trying to do the same concept of what my code below does, but in a simple approach with different way.
My code in MATLAB is:
y=[1 2 3 4]; %first input
OccurancesParameter= 5; % second input , it's always unsigned integer number greater than zero - it's number occurances for each value in the array y
output=repelem(y, OccurancesParameter); % gives me an array according to the repeated Occurance parameter ..
So I want to do the same concept of what my code above does, but simple approach/way in MATLAB, like using for loop or any other simple way, and not using the built in function repelem().
Could anyone please help me out on this? appreciated!

Accepted Answer

Image Analyst
Image Analyst on 23 Jan 2021
Jimmy, try this:
y=[1 2 3 4]; % First input
OccurancesParameter= 5; % second input , it's always unsigned integer number greater than zero - it's number occurances for each value in the array y
output=repelem(y, OccurancesParameter); % gives me an array according to the repeated Occurance parameter ..
y2 = zeros(1, length(y) * OccurancesParameter);
for k = 1 : length(y)
thisy = y(k);
for k2 = 1 : OccurancesParameter
index = (k - 1) * OccurancesParameter + k2;
y2(index) = thisy;
end
end
y2 % Display in command window

More Answers (1)

Adam Danz
Adam Danz on 23 Jan 2021
Edited: Adam Danz on 24 Jan 2021
You can use implicit expansion which is supported in Matlab r2016b and later (more info).
y=[1 2 3 4];
OccurancesParameter= 5;
m = y(:)' .* ones(OccurancesParameter, 1);
output = m(:)'
output = 1×20
1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4
For Matlab releases prior to r2016b,
y=[1 2 3 4];
OccurancesParameter= 5;
m = bsxfun(@times,y(:)', ones(OccurancesParameter, 1));
output = m(:)'
output = 1×20
1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4

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