问题
Possible Duplicate:
Counting values by day/hour with timeseries in MATLAB
This is an elementary question, but I cannot find it:
I have a 3000x25 character array:
2000-01-01T00:01:01+00:002000-01-01T00:01:02+00:002000-01-01T00:01:03+00:002000-01-01T00:01:04+00:00
These are obviously times. I want to reformat the array to be a 3000x1 array. How can I redefine each row to be one entry in an array?
(Again, this is simple, I'm sorry)
回答1:
Other than converting to serial date numbers as other have shown, I think you simply wanted to convert to cell array of strings:
A = cellstr(c)
where c is the 3000x25 matrix of characters.
回答2:
You need to specify a format for the array and feed it to datenum, like this:
>> d = datenum(c,'YYYY-MM-DDTHH:mm:ss')
d =
1.0e+005 *
7.3487
7.3487
7.3487
7.3487
The times are now stored as datenums, i.e. as floating point numbers representing the number of days elapsed since the start of the Matlab epoch. If you want to convert these to numbers representing the fraction of the day elapsed, you can do
>> t = d - fix(d);
and if you want the number of seconds since midnight, you can do
>> t = 86400 * (d - fix(d));
t =
61.0000
62.0000
63.0000
64.0000
来源：https://stackoverflow.com/questions/11673556/formatting-character-arrays