Read CSV with yyyyMMddhhmmss and group months

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Lauren
Lauren on 9 Jan 2022
Commented: Lauren on 12 Jan 2022
Hello! Matlab newbie, so I apologize if this is a simple question.
I've got a 5000 by 1 CSV file filled with numbers in the yyyyMMddhhmmss format. I'm simply trying to group each line by month.
  4 Comments
Lauren
Lauren on 11 Jan 2022
Great points. I want your option 1: to group by month so there are 12 groups.
Yes, you are correct. There are not seconds. It shoulud be yyyyMMddhhmm. Mea Culpa!

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Accepted Answer

Stephen23
Stephen23 on 11 Jan 2022
Here is one way to group by month only, ignoring empty lines of the CSV file:
str = fileread('sample.csv');
tkn = regexp(str,'^(\d{4})(\d\d)','tokens','lineanchors');
tkn = vertcat(tkn{:})
tkn = 5091×2 cell array
{'2020'} {'09'} {'2020'} {'09'} {'2019'} {'08'} {'2019'} {'03'} {'2019'} {'02'} {'2020'} {'06'} {'2019'} {'03'} {'2020'} {'06'} {'2020'} {'06'} {'2020'} {'06'} {'2020'} {'06'} {'2020'} {'06'} {'2020'} {'09'} {'2019'} {'09'} {'2020'} {'06'} {'2019'} {'09'} {'2019'} {'07'} {'2020'} {'06'} {'2019'} {'08'} {'2019'} {'02'} {'2019'} {'03'} {'2019'} {'08'} {'2018'} {'07'} {'2018'} {'08'} {'2018'} {'09'} {'2020'} {'10'} {'2019'} {'07'} {'2018'} {'09'} {'2020'} {'08'} {'2020'} {'09'}
[~,~,grp] = unique(tkn(:,2),'stable')
grp = 5091×1
1 1 2 3 4 5 3 5 5 5

More Answers (1)

KSSV
KSSV on 9 Jan 2022
Read about datevec. This will split the date into year, month, days etc.....from this you can apply the function unique and get them grouped.

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