How to combine multiple files into one .csv

Hello everyone!

I would really appreciate your help on the following:

I have some .csv files with the exact same format (Attached you can find two of them) and I want to combine them to one single file . So far I have attempted the following lines of code but when I run them, I only get the contents of the first file, not both of them.

Is there anything I can do??

filenames={'C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\Airport\Hourly_Stats Airport Tapp .csv','C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\Eptapurgio\Hourly_Stats Eptapurgio Tapp .csv'};
filenames = filenames.';
[~,~,RAW1]=xlsread(filenames{1});
for i=1:size(filenames,1)
[num,~,~]=xlsread(filenames{i});
RAW1=[RAW1;num2cell(num)];
end
xlswrite('C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\CombinedFile.csv',RAW1)

Answer 1

[Jakob B. Nielsen]

If I run your code and pause it after the first execution of the for loop, the num variable is empty, so something might be up with the file formats? At least, it explains why you only get the first file out, as you append empty arrays to your first file every loop.

I assume you want the header from the first file + the numeric data from the first and second files printed out? This does the trick, although I shudder at the file format ;) it should also work if your input is 100 files instead of 2.

filenames={'C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\Airport\Hourly_Stats Airport Tapp .csv','C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\Eptapurgio\Hourly_Stats Eptapurgio Tapp .csv'};
filenames = filenames.';
[~,~,RAW]=xlsread(filenames{1});

for i=1:size(filenames,1)
[~,~,all]=xlsread(filenames{i});
RAW{i+1}=all{2}; 
end
xlswrite('C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\CombinedFile.csv',RAW)

[Daphne PARLIARI]

It worked perfectly, thanks!!

And one extra question please:

Is there a way to also copy the names of the files to the new CombinedFile.csv, in order to tidy it up and keep track which statistics go to which file?

[Jakob B. Nielsen]

It sure is. You have the info already in the filenames variable, just write it to the same file (but specify a cell range, or you will just overwrite the other stuff). For example, this will write to column M:

ranges=['M2:M',num2str(size(filenames,1))+1];
xlswrite('C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\CombinedFile.csv',filenames,ranges);

[Daphne PARLIARI]

Like this?

filenames={'C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\Airport\Hourly_Stats Airport Tapp .csv','C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\Eptapurgio\Hourly_Stats Eptapurgio Tapp .csv'};

filenames = filenames.';
[~,~,RAW]=xlsread(filenames{1});
ranges=['P2:P',num2str(size(filenames,1))+1];
for i=1:size(filenames,1)
[~,~,all]=xlsread(filenames{i});
RAW{i+1}=all{2}; 
end
xlswrite('C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\CombinedFile.csv',RAW, filenames,ranges);

[Jakob B. Nielsen]

I was more thinking like so:

filenames={'C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\Airport\Hourly_Stats Airport Tapp .csv','C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\Eptapurgio\Hourly_Stats Eptapurgio Tapp .csv'};

filenames = filenames.';
[~,~,RAW]=xlsread(filenames{1});
ranges=['P2:P',num2str(size(filenames,1))+1];
for i=1:size(filenames,1)
[~,~,all]=xlsread(filenames{i});
RAW{i+1}=all{2}; 
end
xlswrite('C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\CombinedFile.csv',RAW);
ranges=['M2:M',num2str(size(filenames,1))+1];
xlswrite('C:\PhD\Projects\LIFE ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\CombinedFile.csv',filenames,ranges);

[Daphne PARLIARI]

I got the message:

"Error using xlswrite (line 224)

The specified data range is invalid or too large to write to the specified file format. Try

writing to an XLSX file and use Excel A1 notation for the range argument, for example,

‘A1:D4’.

Error in Tapp (line 175)

xlswrite('C:\PhD\Projects\LIFE

ASTI\C.3\WRF_main_TS_2015_ALL\WRF_Times_ALB+EMISS_FINAL2015\WRF_Thessaloniki_stations_2015\Tapp\Hourly

Stats Tapp All stations.csv',filenames,ranges);

"