converting a column of text dates and time to actual day fraction

How can I convert a column of text that is in the form of 'yyyy-MM-ddTHH:mm:ss.SSSZ' (expample: 2021-03-05T19:09:32.840Z) to something I can use as an X-axis on a plot. I'm kind of new at this. I'm really more concerned with the tiime of day rather than the year.

Thanks,

Shane

Answer 1

[Cris LaPierre]

Convert it to a datetime, and use that as your x value.

T = "2021-03-05T19:09:32.840Z";
x = datetime(T,"InputFormat",'yyyy-MM-dd''T''HH:mm:ss.SSS''Z')

x = datetime
   05-Mar-2021 19:09:32

plot(x,5,'*g')

[Shane Luker]

It didn't work exactly but you got me looking in the right area. The following was what I used to read the first column of the text data: text(:,1)

I converted the text to a DateString. The infmt was the format of that column of text. But the datetime functions is what I used. The time variable didn't show the fractional seconds by default. I had to use time.format. Thanks for your help though.

DateString = text(:,1);

infmt = 'yyyy-MM-dd''T''HH:mm:ss.SSS''Z';

time = datetime(DateString,"InputFormat",infmt);

time(1,:) = [];

time.Format = 'HH:mm:ss.SSS';

[Cris LaPierre]

More lines of code than you need, but if it works for you, that's good enough for me.