How to read time as string data from excel file

Question

Yasuyuki Hamanaka 2021-5-24

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https://ww2.mathworks.cn/matlabcentral/answers/837903-how-to-read-time-as-string-data-from-excel-file

评论： Yasuyuki Hamanaka 2021-5-24

I used readtable to read time from excel spread sheets. The time was converted to double like e.x. But I want to read time as original form. How does read time as string?

e.x 10:11:09 AM => 0.42858

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Answer 1

Yutaka Yamada 2021-5-24

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https://ww2.mathworks.cn/matlabcentral/answers/837903-how-to-read-time-as-string-data-from-excel-file#answer_707053

在 MATLAB Online 中打开

readTime.xlsx

How about the below code if you want to use readtable?

opts = detectImportOptions('readTime.xlsx');
opts.VariableTypes = 'datetime'; 
T = readtable('readTime.xlsx', opts);
for i = 1:3
    a = T{i, 1};
    a.Format = 'HH:mm:ss a';
end

I've attached the Excel file that I've used for this test also.

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Yasuyuki Hamanaka 2021-5-24

Thank you both for answering. Actually the spreadsheet is the picture below. I want to read Var1 as date, Var2 as time and Var 3 and 4 asdouble. Do you know how to specify the format of each columns, if there's multiple variables?

Yasuyuki Hamanaka 2021-5-24

在 MATLAB Online 中打开

I found the function setvaropts.

opts = detectImportOptions('input.xlsx');
opts = setvartype(opts,{'Var2'},'datetime');
opts = setvaropts(opts,{'Var2'},'DatetimeFormat','HH:mm:ss a');
schedule = readtable('input.xlsx',opts);

Thank you everyone for helping me. Your information were very helpful and I learned a lot.

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Answer 2

Sulaymon Eshkabilov 2021-5-24

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https://ww2.mathworks.cn/matlabcentral/answers/837903-how-to-read-time-as-string-data-from-excel-file#answer_707033

Hi,

You should try using xlsread() in this case. In fact, xlsread is slower than readtable().

Then you can employ datenum() and datestr() if necessary.

Good luck.

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Yasuyuki Hamanaka 2021-5-24

Thank you for answering my question. I want to use readtable because the amount of data is so large that reading data takes long. But I didn't know the fucntion of datenum() and datestr(), so it is very helpful for me.

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