Adapting the datetime function

Hi everybody!

I got: a string representing a time in the format of 'dd.MM.yyyy HH:MM:SS.SSS' (actually not only one string, but a whole list)

I'd like to: transform my string into a datetime with the help of the function "datetime"

That's what I tried so far:

With the following line of code I'm always getting the error message "Error using datetime (line 639) Input data must be a numeric array, a string array, a cell array containing character vectors, or a char matrix."

date=datetime(t.r(:,1),'Inputformat','dd.MM.yyyy HH:MM:SS.SSS');

Unfortunately: I don't know how to adapt the datetime function properly! Can you please help me?

Answer 1

[Paolo]

You must use the correctly specifiers for 'InputFormat', mm for minutes and ss for seconds.

 str = "13.07.2018 09:59:30.333"
 datetime(str,'InputFormat','dd.MM.yyyy HH:mm:ss.SSS')

[jrbbrt]

So basically my string looks like

"13.07.2018 10:00:22.333"

and though I adapt everything like you said, I unfortunately still get the same error message. Do you have an idea why? Or how to work around this?

[Paolo]

Apologies, I missed that the milliseconds are preceded by a full stop and not a colon.

Try:

 datetime(str,'InputFormat','dd.MM.yyyy HH:mm:ss.SSS')

Answer 2

[Steven Lord]

Define a variable and show us the class and size of that variable. You can show both using the whos function.

z = t.r(:,1);
whos z

The error message states:

"Error using datetime (line 639) Input data must be a numeric array, a string array, a cell array containing character vectors, or a char matrix."

To satisfy the requirement to be valid input data to the datetime function, z must be one of a numeric array (check with isnumeric), a string array (check with isstring), a cell array containing character vectors (check with iscell and iscellstr), or a char matrix (check with ischar and ismatrix).

From your description my guess is that you have a cell array containing a string array.

>> D = datetime({"13.07.2018 09:59:30.333"})
Error using datetime (line 639)
Input data must be a numeric array, a string array, a cell array containing
character vectors, or a char matrix.

If that's the case, you may want to switch to using just a plain string array.

>> D = datetime(["13.07.2018 09:59:30.333"; "10.08.2018 13:15:47.123"], ...
                'InputFormat', 'dd.MM.yyyy HH:mm:ss.SSS')