How to reduce time of calculation? (code includes 'for' loop with cell function)

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Kazi Alam 2021-5-6

0
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https://ww2.mathworks.cn/matlabcentral/answers/823410-how-to-reduce-time-of-calculation-code-includes-for-loop-with-cell-function

回答： Kazi Alam 2021-5-7

Hallo ;), Thanks in advance

I have a data table 'P' (2772774x17) and generated another table 'aT' where the length is the unique elments from column 1 of 'P' and unique values from column 2 of 'P' as width(header). My purpose is to count the occurence of column 2 values of 'P' for each column 1 unqiue values of 'P' and save the occurences in 'aT'. This takes a very long time. Is there a possiblity to do it in a different way to save the time. Code given below:

for i=1:length(uniqueP)
count_string = cellfun(@(x) sum(ismember(P.Typ(ismember(P.ProjektID,...
    uniqueP(i)),:),x)),  aT.Properties.VariableNames(2:end));
% Replacing rows of a table
aT(i,2:end) = num2cell(count_string);
end

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Sergey Kasyanov 2021-5-6

What data types are stored in P.ProjektID and P.Typ columns?

Kazi Alam 2021-5-6

编辑：Kazi Alam 2021-5-7

Hi @Sergey Kasyanov

P.ProjektID >> double

P.Typ >> Cell

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Answer 1

Kazi Alam 2021-5-7

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/823410-how-to-reduce-time-of-calculation-code-includes-for-loop-with-cell-function#answer_694490

I changed the data search order. Earlier, the code was checking the uniqueness of the duble array then the string array. Now, the process is reveresed and it saved me hours.