How do I import a timestamp from Excel/csv?

15 次查看（过去 30 天）
Dan Getz
Dan Getz 2017-7-6
评论： Walter Roberson 2017-7-11
I have a .csv file with 6 columns of data and 14000 or so rows. I attached a file with a screenshot of the spreadsheet. I have tried
data=load('My_Spreadsheet_Name');
timestamp=data(:,1);
and since learned why that won't work. I then tried
xlsread('My_Spreadsheet_Name');
and that worked for everything that wasn't a timestamped piece of data. The 5 columns on the right imported into Matlab just fine but Matlab skipped over the 1st set of data that I needed.
This Link had a similar question but I'm either too dumb to figure out the formatting properly or I'm trying to import differently formatted data.
I'm hoping someone smarter than me will be able to figure out what I'm doing incorrectly.

请先登录，再回答此问题。

回答（2 个）

C.J. Harris
C.J. Harris 2017-7-6
Try this:
[NUMERIC, TXT, RAW] = xlsread('My_Spreadsheet_Name');
You'll find the timestamps in both the TXT and RAW outputs. If you call xlsread the way you are, then you'll just get the numeric data.
  2 个评论
Dan Getz
Dan Getz 2017-7-6
编辑：Dan Getz 2017-7-6
Thank you so much. That worked for me. Is there a way to import the data as being double? I'm trying to interpolated based on 3 hr data and I can't interpolate with cell data.
Walter Roberson
Walter Roberson 2017-7-7
time_col = raw(:,1)
num_cols = cell2mat( raw(:,2:end) );
Now you can convert time_col with datenum() or (better) datetime()

请先登录，再进行评论。

Peter Perkins
Peter Perkins 2017-7-7
The best way to do this in a recent version of MATLAB is to use readtable, and create datetimes. This will free you from all the issues of converting excel serial dates.
  4 个评论
显示 2更早的评论
Peter Perkins
Peter Perkins 2017-7-11
For a CSV, you can also specify the 'Format' parameter in the call to readtable, with something like %{'M/d/yy h:mm a'}D for that field.
Or quick and dirty: t.Date.Year = t.Date.Year + 2000
Walter Roberson
Walter Roberson 2017-7-11
readtable is documented to interpret format strings the same way as textscan, and unless it has recently changed, textscan %D format specifiers cannot handle embedded spaces.
Ah.... testing now, I see that a '%{M/d/yy hh:mm aa}D' format spec can work for textscan, but only if whitespace has been set to exclude spaces.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Spreadsheets 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