Datastore won't recognize datetime in CSV files (Matlab 2019b)
조회 수: 10 (최근 30일)
이전 댓글 표시
Hello,
I'm trying to evaluate a datastore of CSV data that I saved with Matlab using writetable. One column contains datetimes and an example of the files' contents is this:
29-Jul-1983 00:00:00,BHP AT EQUITY,MOV_AVG_50D,0.8979
31-Aug-1983 00:00:00,BHP AT EQUITY,MOV_AVG_50D,0.9029
30-Sep-1983 00:00:00,BHP AT EQUITY,MOV_AVG_50D,0.9106
31-Oct-1983 00:00:00,BHP AT EQUITY,MOV_AVG_50D,0.9154
30-Nov-1983 00:00:00,BHP AT EQUITY,MOV_AVG_50D,0.9227
30-Dec-1983 00:00:00,BHP AT EQUITY,MOV_AVG_50D,0.9311
I tried the following code and received the subsequent error in the postscript. When I use datastore with "DatetimeType" set to "text," it works, but that is obviously inefficient. Can someone enlighten me on how to get this to work?
Thank You,
Michael
This code works
ds = datastore('tall.csv','DatetimeType','text');
tds = tall(ds);
u = unique(tds.FIELD);
U = gather(u);
This code fails
ds = datastore('tall.csv');
tds = tall(ds);
u = unique(tds.FIELD);
U = gather(u);
The error is
Evaluating tall expression using the Parallel Pool 'local':
- Pass 1 of 1: 0% complete
Evaluation 0% complete
Error using matlab.io.datastore.TabularTextDatastore/readData (line 77)
Unable to read the DATETIME data using the locale setting for your system: 'en_US'
If the data contains month or day names in a language foreign to this locale, use the 'DateLocale' parameter to specify the correct locale.
Learn more about errors encountered during GATHER.
Error in matlab.io.datastore.TabularDatastore/read (line 120)
[t, info] = readData(ds);
Error in tall/gather (line 50)
[varargout{:}, readFailureSummary] = iGather(varargin{:});
댓글 수: 1
Walter Roberson
2019년 8월 27일
Which release are you using?
Which column does FIELD correspond to?
The code seemed to work for me.
채택된 답변
추가 답변 (5개)
Nimit Dhulekar
2019년 8월 27일
Hi Michael,
Are you executing these set of commands from outside the US? If so, the datetime formats available would be different from the ones available in the US. Try the following command:
datetime('29-Jul-1983 00:00:00')
You might quite possibly get an error similar to the one you posted. To get around this issue, you can supply "DatetimeLocale" as a Name-Value pair when constructing the datastore.
ds = datastore('tall.csv','DatetimeLocale','en_US');
Hope that helps!
-Nimit
댓글 수: 0
Michael
2019년 8월 28일
댓글 수: 1
Walter Roberson
2019년 8월 28일
Try all of the months: there might be a difference only for a few of them.
Michael
2019년 8월 28일
댓글 수: 1
Walter Roberson
2019년 8월 28일
And if you use tds.FIELD does it go back to failing? Is it possible that it has decided that tds.FIELD is a datetime ?
Michael
2019년 8월 28일
댓글 수: 6
Steve Gardner
2019년 12월 5일
I to have a simular issue CSV files with the date format of yyyy/MM/dd, datastore converts this to MM/dd/yyyy which is fine but for anything after the 12th day of the month it gives the value as NaN, basically it gets the month and day fields mixed up.
I too gave up and converted the CSV file date field to MM/dd/yyyy, just need to remember to do this evey time I get a new CSV file, bit of a pain really.
참고 항목
카테고리
Help Center 및 File Exchange에서 Dates and Time에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!