converting hhmmss to seconds

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Daniel 2015-10-18

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编辑： Stephen23 2015-10-18

I have a file with the time in the following format hhmmss.ss. So for example, 175012.76 is 17 hours, 50 minutes and 12.76 seconds. I'm reading the file in using dlmread. How do I convert that to seconds? Thanks

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Daniel 2015-10-18

Maybe not the most elegant, but I finally did this:

time_wind = dlmread([path,file]); %read in 25 Hz wind file

time_all = num2str(time_wind(:,1)*100);

time_sec = str2num(time_all(:,5:8))/100;

time_min = str2num(time_all(:,3:4));

time_hr = str2num(time_all(:,1:2));

time_sfm = 3600*time_hr + 60*time_min + time_sec;

time_wind(:,1)=time_sfm;

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Answer 1

Stephen23 2015-10-18

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https://ww2.mathworks.cn/matlabcentral/answers/249306-converting-hhmmss-to-seconds#answer_196395

编辑：Stephen23 2015-10-18

在 MATLAB Online 中打开

Although you do not give any useful information at all in your question about the file format or how many of these numbers there are and how they might be arranged, here are two possible solutions for you to try out.

Method One: from decimal value

Simply convert it into hours, minutes and seconds, and then sum them:

>> val = 175012.76;
>> hrs = floor(val/10000)
hrs =                   17
>> mns = floor(rem(val,10000)/100)
mns =                   50
>> scs = rem(val,100)
scs =     12.7600000000093
>> 60*60*hrs+60*mns+scs
ans =             64212.76

Method Two: read the file as characters

It might be easier to read the file using textscan, which would allow you to import the values as strings, which can then be parsed directly into hours, minutes and seconds. This is much faster and more efficient than separate calls to str2num, cellfun or the like:

>> str = '175012.76'
str = 175012.76
>> vec = sscanf(str,'%2d%2d%f')
vec =
         17
         50
         12.76
>> sum([60*60;60;1].*vec)
ans =    64212.76