How to change the date-format of an existing file ?

Dear community,

Applying the 'readcell'-function to one of my existing files (here: .xls and .xlsx- files) I get the following error:

'Error using readcell (line 151)

Could not recognize the date/time format of '15-März-2019'. You can specify a format using the 'InputFormat' parameter. If the date/time text contains day, month, or time zone names in a language foreign to the 'en_US' locale, those might not be recognized. You can specify a different locale using the 'Locale' parameter.'

How can I change the it? Please consider the attachment.

Answer 1

[Walter Roberson]

datetime('15-März-2019', 'Locale', 'de')

ans = datetime
   15-Mar-2019

So use readcell() with 'Locale', 'de'

[Haron Shaker]

Hello Walter,

Thanks for the answer.

I tried it with: readcell(file,'Locale', 'de'). It says:

Error using readcell (line 151)

Unknown Parameter 'Locale'.

Did I understand it right, with 'use readcell() with 'Locale', 'de'?

[Walter Roberson]

It looks like for text files you would use DateLocale, and that there is no corresponding parameter for spreadsheet files.

You might need to

c = readcell(file, 'DateTimeType', 'text');
c(:,2) = cell2mat( datetime(c(:,2), 'Locale', 'de') );

[Haron Shaker]

Hey Walter,

Thanks again!

Unfortunately, I still get an error:

'Error using datetime (line 668)

Input data must be a numeric array, a string array, a cell array containing character vectors, or a char matrix.

Error in trytorun (line 24)

xlsData(:,2) = cell2mat( datetime(xlsData(:,2), 'Locale', 'de') );'

My code is the following:

list = readcell('createxls.xlsx')
meds = {}; 
tempmeds = {};
meds2 = {}; 

for i = 1:length(list)
    
    tempmeds = [];
    meds2 = []; 
    
    tempmeds = meds;   
    meds = []; 
    
    file = list{i}; 
    xlsData = readtable(file, 'DateTimeType', 'text'); 
    xlsData(:,2) = cell2mat( datetime(xlsData(:,2),  'Locale', 'de') );

    xlsTxtData = xlsData(strcmp(xlsData(:,3), 'txt'), :);
    
 
    pattern = ["clozapin","clozaril","clopine","fazaclo","denzapine"]; 
    meds2 = a.findClozapineInCellArray(xlsTxtData, meds, pattern); 
    meds = [tempmeds; meds2]; 
end 

Do you see the problem?

Best!

[Walter Roberson]

    xlsData(:,2) = cell2mat( datetime(xlsData{:,2},  'Locale', 'de') );

Also, in your code, a is not defined.

[Haron Shaker]

Thanks!

You're right, in this cutout it is not defined.

I still get an error:

Error using datetime (line 546)

Wrong number of arguments.

Error in trytorun (line 27)

xlsData(:,2) = cell2mat( datetime(xlsData{:,2}, 'Locale', 'de') );

By the way: Does it make a difference in using 'readcell' or 'readtable'?

[Walter Roberson]

readtable returns a table object, whereas readcell returns a cell array in which each entry is a separate cell, so Yes, it does matter.

Using {:,2} would be wrong for readcell but I think it should work for readtable as it should return the second variable as a single argument.