Read time with colon from .txt file

Question

Hendrik 2013-12-5

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/108833-read-time-with-colon-from-txt-file

编辑： per isakson 2013-12-6

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.

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Answer 1

per isakson 2013-12-5

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https://ww2.mathworks.cn/matlabcentral/answers/108833-read-time-with-colon-from-txt-file#answer_117456

编辑：per isakson 2013-12-6

在 MATLAB Online 中打开

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

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Hendrik 2013-12-5

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 2013-12-5

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

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Answer 2

dpb 2013-12-5

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/108833-read-time-with-colon-from-txt-file#answer_117454

在 MATLAB Online 中打开

>> 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

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Hendrik 2013-12-5

在 MATLAB Online 中打开

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.