MATLAB: “Error using textscan: Badly formed format string” with R2012b

formatspecMATLABtextscan

Hello,
I want to read about 14 million rows of data from an .csv file an save it in a cell array.
The .csv file looks like this:
vehicle_id;_date;measurement_start;measurement_end
100454;2016-09-11T15:01:14.769Z;2.620;6.400
100454;2016-09-11T15:01:15.769Z;7.820;10.400
100452;2016-09-11T15:01:16.769Z;3.620;9.400
100453;2016-09-11T15:01:17.769Z;4.620;5.400
100454;2016-09-11T15:01:18.769Z;20.620;25.400
100458;2016-09-11T15:01:19.769Z;8.620;16.400
100454;2016-09-11T15:01:20.769Z;45.620;50.400
This is my Script to create the cell Array:
clear;
[filename, pathname] = uigetfile({'*.csv','All Files (*.*)'}, 'Pick a file');
filename = [pathname filename];
delimiter = ';';
startRow = 2;
formatSpec = '%f %{yyyy-mm-ddTHH:MM:SSZ}D %f %f %*{^\n}';
fileID = fopen(filename,'r');
dataArray = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'HeaderLines' ,startRow-1, 'ReturnOnError', false);
fclose(fileID);
The mistake is in formatSpec when I try to format the Date and Time.
It's one easy mistake, but I can't figure it out.

Best Answer

Use this instead:
formatSpec = '%f %s %f %f %*{^\n}';
and convert the dates afterwards using datenum. I do not remember if datenum of R2012b can handle this format, but in case of troubles or if this is time critical, you can use FEX: DateStr2Num (use the format spec 31).
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