How can I get MATLAB to plot a date on the x-axis?

Question

Sandy 2013-10-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/90980-how-can-i-get-matlab-to-plot-a-date-on-the-x-axis

评论： dpb 2020-1-28

I have a dataset with column1 = date and column2 = data. The problem is that my date is in yyyymmdd format. How can I get MATLAB to plot the date correctly in the x-axis?

Thank you in advance! :)

2 个评论
显示无隐藏无

sixwwwwww 2013-10-21

Do you have ur data in txt file or excel file?

Sandy 2013-10-21

It's a text file.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

dpb 2013-10-21

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/90980-how-can-i-get-matlab-to-plot-a-date-on-the-x-axis#answer_100412

在 MATLAB Online 中打开

First convert the text string date format to Matlab serial dates --

doc datenum

Then plot with that value as the x-axis value and format the dates as desired via

doc datetick
dn=datenum(data(:,1),'yyyymmdd');
plot(dn,data(:,2))
datetick('x','keepticks','keeplimits')

Salt to suit...

2 个评论
显示无隐藏无

William 2020-1-28

Thank you! This had been driving me nuts, but now works perfectly.

dpb 2020-1-28

This answer is now out of date...use the new(ish) datetime class instead of datenum

请先登录，再进行评论。

Answer 2

Sandy 2013-10-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/90980-how-can-i-get-matlab-to-plot-a-date-on-the-x-axis#answer_100424

Hi dpb. I tried it this way, but for some reason it's plotting all my data as one date.

2 个评论
显示无隐藏无

Sandy 2013-10-21

Nevermind, I got it. I had to convert my number to strings first. Thank you! :)

dpb 2013-10-21

在 MATLAB Online 中打开

Oh, didn't think about the first column being integer, granted...just for the record, alternatively, you could separate out the separate fields and use the

datenum(y,m,d,h,mn,s)

form to generate the serial numbers.

请先登录，再进行评论。

Answer 3

Dainty Daisy Calgas 2017-12-3

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/90980-how-can-i-get-matlab-to-plot-a-date-on-the-x-axis#answer_294371

Hello, how could I plot a quarterly data with column1, written as Q1:1991 up to Q4:2016, then my column2 is my data., please I really need help, it was in the excel.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

dpb 2017-12-3

Better form would be to create a new question, but it is at least related so I'll consider it here as "close enough"... :)

Problem first is we need to know how the date data are actually stored and imported. Since the date of the original Q, TMW has introduced the datetime class/object and improved graphics routines to be datetime aware so things are different now than then...

请先登录，再进行评论。