Export data from CSV file as a vector.

I am using an app to try different sources of energy, the problem is that the app exports the data in CSV format, even though it is okay to get the amplitude from the file, it isn't working to get the time. It is in HH:MM:SS.FFF, and I am not being able to export it to matlab as a variable (so I can plot time vs amplitude). I have to export the B column as a vector, any idea?

[Konstantinos Sofos]

Could you load a CSV as an example since we do not have any code from your side?

Answer 1

[Konstantinos Sofos]

As I miss your sample of data, I have created one by myself (attached Data.csv). Below you can find a script that read this type of data.

fid = fopen('Data.csv');
if fid > 0
    data = textscan(fid,'%d %s %f %d','Delimiter',',');
    fclose(fid);
end

refTime=cellfun(@(x) datenum(x,'mm/dd/yyyy HH:MM:SS:FFF'),data(:,2),'UniformOutput',0);

plot(refTime{:},data{:,3})

datetick('x','mm/dd/yyyy HH:MM:SS:FFF');

data will be a cell array, with its second column containing all of the date strings of the format

'01/09/2014 15:27:18:322'

To convert this to number you use the datenum

Regards

[Konstantinos Sofos]

After your sample file you can load your data as

fid = fopen('SeismometerData.csv');
if fid > 0
    data = textscan(fid,'%s %s %f %f %f','Delimiter',',','HeaderLines',1);
    fclose(fid);
end
Timestamp = strcat(data{:,1},'', data{:,2});
TimestampNum=cellfun(@(x) datenum(x,'yyyy:mm:ddHH:MM:SS.FFF'),Timestamp,'UniformOutput',0);
TimestampNum = [TimestampNum{:}];
amplitude = [data{:,5}]';
plot(TimestampNum,amplitude)
ylabel('Amplitude')
xlabel('Clock - Time')
title('Seismometer Data')
grid on
datetick('x','HH:MM:SS');

and the result figure will be

As a reference may you have a look into the following functions textscan, cellfun and datetick.

Regards