MATLAB CSV read error

Question

At first, I would like to say that this is not a duplicate of this: Reading CSV files with MATLAB?

In my script, I am trying to read a CSV file (sensor data). It is of the format:

2015-10-08 01:00:00.000,-0.762,-0.68,-0.234
2015-10-08 01:00:00.013,-0.762,-0.676,-0.234
2015-10-08 01:00:00.025,-0.762,-0.672,-0.234
2015-10-08 01:00:00.038,-0.762,-0.672,-0.23

and suddenly I get this error:

Error using dlmread (line 147)
Mismatch between file and format character vector.
Trouble reading 'Numeric' field from file (row number 1, field number 1) ==> 
 ,-0.02,-0.004,1.004\n

Error in csvread (line 48)
m=dlmread(filename, ',', r, c);

Error in getAvgData (line 17)
    rawData = csvread([filePath, '/', fileList.name]);

 Error in precomputeProcess (line 31)
                getAvgData;

This code used to work well without this error and this is the first time I am seeing this. I am not sure if textScan would be of any help. here is my code snippet:

for k = 1:length(hourSampleRateList)
hourSampleRate = hourSampleRateList(k);
disp(['Start at sampling rate: ', num2str(hourSampleRate)]);
for hour = startHour:endHour
    hourStr =  num2str(hour,'%02i');

    filePath = fullfile(pwd, username, 'MasterSynced', yearStr, monthStr,dayStr,hourStr);
    fileList = dir([filePath, '/RawDataFloat*.csv']);
    if (isempty(fileList))
        continue;
    end
    rawData = csvread([filePath, '/', fileList.name]);
    avgData = zeros(ceil(length(rawData)/hourSampleRate), 4);

    j = 1;
    for i = 1:hourSampleRate:length(rawData)-1;
        avgData(j, :) = mean(rawData(i:i+hourSampleRate-1, :));
        j = j + 1;
    end

    filePath = fullfile(pwd, username, 'MasterSynced', yearStr, monthStr,dayStr,hourStr);
    myPath = [filePath, '\Avg', num2str(hourSampleRate, '%03i'), '-', fileList.name];

    if exist(myPath, 'file') == 2
        delete(myPath);
    end
    dlmwrite(myPath,avgData,'delimiter',',','precision','%.3f');
    disp(['Day-Hour(', dayStr, '-', hourStr, '): completed.']);
end
end

Any help or info would be helpful.

score 1 · Answer 1 · answered Mar 15 '18 at 08:03

M = csvread(filename) reads a comma-separated value (CSV) formatted file into array M. The file must contain only numeric values.

Your first column is a date, not a numerical value.

M = csvread(filename,R1,C1) reads data from the file starting at row offset R1 and column offset C1.

So you may skip the first column by using rawData = csvread([filePath, '/', fileList.name],0,1);

Also if your version is < 2016b, this MATLAB Answer suggests to use textscan instead, with 'HeaderLines',8 and appropriate format discriptor, 'Delimiter', and if necessary, 'EndOfLine' declarations.

MATLAB CSV read error

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