How to read time as string data from excel file

2021 5 24
2 个回答
回答已采纳
更新时间：2021 5 24
17 次查看（30 天）

0 个投票

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

请先登录，再回答此问题。

 采纳的回答

Yutaka Yamada
Yutaka Yamada 2021-5-24

1 个投票

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.

3 个评论
显示 1更早的评论 隐藏 1更早的评论

Siddharth Bhutiya
Siddharth Bhutiya 2021-5-24
You should use readtable, xlsread is not recommended and is there only for legacy support. Two comments on the code above 1. For a datetime array you can directly change the Format of the entire array at once, you do not need to do it element by element. 2. You can directly specify the display format in opts as follows:
>> opts = detectImportOptions('readTime.xlsx');
>> opts.VariableTypes = 'datetime';
>> opts.VariableOptions.DatetimeFormat = 'HH:mm:ss a';
>> T = readtable('readTime.xlsx', opts)
T =
3×1 table
Var1
___________
10:11:09 AM
10:11:09 AM
10:11:09 AM
Yasuyuki Hamanaka
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
Yasuyuki Hamanaka 2021-5-24
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.

请先登录，再进行评论。

更多回答（1 个）

1 个投票

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.

1 个评论
显示 -1更早的评论 隐藏 -1更早的评论

Yasuyuki Hamanaka
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.

请先登录，再进行评论。

类别

在 帮助中心 和 File Exchange 中查找有关 Data Type Identification 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by