Read time with colon from .txt file

Hello, I have an input file with data that contains the time, but it is in the format of the current time, thus 12:25:25.17 for example (12 hours, 25 minutes, 25 seconds and 17 miliseconds) but when matlab tries to read the column of data, it only takes the 12, not the rest. So i tried to replace all : for a space and wanted to convert the hours hours, minutes and seconds to miliseconds so that you get one column that matlab can read. however when i tried to replace the : in the txt file, the output is only shown in the command window. I cant figure out how to save it in an array (so making from 1 array 4 arrays). Or if there is an easier way for matlab to read these numbers containing several : each, that would be handy.

Answer 1

[per isakson]

Try

    fid = fopen( 'data.txt' );
    cac = textscan( fid, '%s%f%f%f%f', 'CollectOutput', true );
    sts = fclose( fid );
    sdn = datenum( char(cac{1}), 'HH:MM:SS.FFF' );
    vec = datevec( char(cac{1}), 'HH:MM:SS.FFF' );

where data.txt contains

    12:25:25.17 1 2 3 4
    12:25:26.99 5 6 7 8

Note:

Above, char(cac{1}) may be replaced by cac{1}, since Doc (R2013a) on datevec says:

    DateVector = datevec(DateString,formatIn)

and

    DateString — Date stringsstring | cell array of strings

[Hendrik]

Thanks, this works perfectly,

Although i am not sure what the numbers in column 1, 2 and 3 from the array vec mean. (But that does not matter because the other 3 columns give everything i need.) Thanks again.

[per isakson]

"column 1, 2 and 3 from" are default values for year, month and day. See the help.

Answer 2

[dpb]

>> s='12:25:25.17'
>> fmt=[repmat('%d:',1,2) '%d.%d'];
>> sscanf(s,fmt)
ans =
  12
  25
  25
  17
>>

Salt the format to suit the full record, of course. And, if you need yet more flexibility,

doc textscan

[Hendrik]

Your method will work if you can import the full numbers including the colons to matlab. But the problem is that these numbers are in the .txt file and in matlab only takes the hours. If i try

Data = load('data.txt')
time = Data(:,1)

Then it will only show time(1)=12, time(2)=12, time(3)=12 etc. So for it to work, i would need to add a ' before and after the entire first column in the .txt file.

[dpb]

doc textscan
doc fscanf

Use fopen() to open the file, I simply demonstrated the format string to handle the time format.