您正在关注此问题

您将在关注的内容源中看到更新。
您可能会收到电子邮件，具体取决于您的通信预设项。

Convert date from number to format in matllab

2 次查看（过去 30 天）

显示更早的评论

NN 2021-1-31

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab

⋮

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab

编辑： Walter Roberson 2021-2-5

采纳的回答： Walter Roberson

I have original time and date format as mentioned below:

2/17/2020 9:48:18 AM

I did forecasting using this , and after forecasting output date in the plot appears in number format like :

43878.4085416667

How can i convert it back to original date and time format ?

9 个评论
显示 7更早的评论隐藏 7更早的评论

Walter Roberson 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297068

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297068

How did you do the forecasting with it?

Did you convert the date/time t numeric using datenum() ? If so, only do that if the forecasting routines do not support datetime objects, and otherwise use datetime() .

NN 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297083

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297083

在 MATLAB Online 中打开

yes, i converted using datenum()

Data=readtable('data.xlsx'); 
testdates = Data{1:end,1};
date_num = datenum(testdates);
date_num2 = datenum(testdates)+table2array(Data(1:end,2))./(24*3600);

NN 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297088

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297088

在 MATLAB Online 中打开

then i used below code to plot it :

figure
plot(out)
hold on
plot(in,'.-')
hold off

NN 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297093

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297093

编辑：NN 2021-1-31

在 MATLAB Online 中打开

but it appears like serial numbers :i want to convert it to date and time format :i tried the below code but unable to plot since it is character array(pic attached) :If i convert it to double again it becomes NAN since it has string values:

o=datestr(in);
S = double(out);
S1=datestr(S);
figure
plot(out)
hold on
plot(in,'.-')
hold off

Walter Roberson 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297103

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297103

在 MATLAB Online 中打开

date_num2 = testdates + seconds(Data{:,2});

Now if possible use date_num2 in the forecasting, and plot with

plot(date_num2, in)

NN 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297468

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297468

thank you for your response.It worked for input date ,but didnt work for the output

out is date value generated after forecasting , and how can i convert this output back to date time format .

Walter Roberson 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297483

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297483

在 MATLAB Online 中打开

Ran in:

How are you generating the date value from forecasting ?

The values near 43878.4085416667 suggest to me,

datetime(43878.4085416667, 'convertfrom', 'excel')
ans = datetime
   17-Feb-2020 09:48:18

but why are you getting Excel dates at all???

NN 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297533

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297533

This is the output i am getting . i need to convert it back to date time format

NN 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297538

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297538

i tried converting it to character array using below code ,

S = double(out);

S1=datestr(S);

but still not able to plot

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Walter Roberson 2021-1-31

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#answer_610638

⋮

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#answer_610638

在 MATLAB Online 中打开

outd = datetime(out, 'convertfrom', 'excel');
plot(outd)

10 个评论
显示 8更早的评论隐藏 8更早的评论

NN 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297578

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297578

thank you .It worked

Walter Roberson 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297593

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1297593

Your code should be changed so that it does not produce Excel date numbers from the forecast. However, you are not being cooperative in identifying how it is getting Excel date numbers as output values, so I stopped caring.

NN 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1298513

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1298513

编辑：NN 2021-1-31

:-(

I will definitly change the code .But please advise how to do it .i am not an expert in programming , thats why

Walter Roberson 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1298543

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1298543

The first step would be to describe how you are currently doing the forecasting. Which I already asked about twice before.

NN 2021-1-31

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1298553

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1298553

LSTM forecasting

Walter Roberson 2021-2-1

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1298588

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1298588

The error is on line 7, character #11.

NN 2021-2-1

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1298598

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1298598

sorry , i didnt understand

Walter Roberson 2021-2-1

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1298683

⋮

链接

此评论的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731608-convert-date-from-number-to-format-in-matllab#comment_1298683

This is the information we, as outside observers, have so far:

You have a datetime() vector named in
Your results from your forecasting is named out
Your results are in Excel date numbers
You are using lstm forecasting.

(4) tells us that you must have created layers, and called trainNetwork(), and probably called predictAndUpdateState() https://www.mathworks.com/help/deeplearning/ug/time-series-forecasting-using-deep-learning.html

However, it does not tell us what you passed to trainNetwork(), and it does not tell us what layers you used.

So... we need to read your mind to figure that out. And when I read your mind, and your memory of what code you wrote, I figured out that your bug is in character #11 of line 7 of your code.

NN 2021-2-5