Question

I am reading a .xls file and then procesing it inside and rewriting it in the end of my program. I was wondering if someone can help me to parse the dates
as my input file name is like file_1_2010_03_03.csv

and i want my outputfile to be

newfile_2010_03_03.xls

is there a way to incorporate in matlab program so i do not have to manually write the command
xlswrite(‘newfile_2010_03_03.xls’, M);
everytime and change the dates as i input files with diff dates
like
file_2_2010_03_04.csv.

Maybe i was not clear>
I am using uigetfile to input 3 diff files in format
file_1_2010_03_03.csv,file_2_2010_03_03.csv,file_3_2010_03_03.csv

Now i am processing the file inside my program and writing 4 output files
with names newfileX_3_2010_03_03.xls,newfileXY_3_2010_03_03.xls,newfileXZ_3_2010_03_03.xls,
newfileYZ_3_2010_03_03.xls

so my dates are not current date , but i need that from the input file and append that to newname for my xlswrite.

so was wondering if there is a way i can write a generic

xlswrite (‘xxx ‘ M);
which will pick the name i want instead of me having 2 modify the name’ xxx’ everytime i input a new file

Thanks

Thanks

Answer 1

It looks like I misunderstood what you meant with ‘file_1’, ‘file_2’ – I thought the numbers 1 and 2 had some kind of importance.

oldFileName = 'something_2010_03_03.csv';
%# extract the date (it's returned in a cell array
theDate = regexp(oldFileName,'(\d{4}_\d{2}_\d{2})','match');
newFileName = sprintf('newfile_%s.xls',theDate{1});

Older Version with Explanations

I assume that the date in all your files is the same. So your program would go

%# load the files, put the names into a cell array
fileNames = {'file_1_2010_03_03.csv','file_2_2010_03_03.csv','file_3_2010_03_03.csv'};

%# parse the file names for the number and the date
%# This expression looks for the n-digit number (1,2, or 3 in your case) and puts
%# it into the field 'number' in the output structure, and it looks for the date
%# and puts it into the field 'date' in the output structure
%# Specifically, \d finds digits, \d+ finds one or several digits, _\d+_
%# finds one or several digits that are preceded and followed by an underscore
%# _(?<number>\d+)_ finds one or several digits that are preceded and follewed 
%# by an underscore and puts them (as a string) into the field 'number' in the 
%# output structure. The date part is similar, except that regexp looks for 
%# specific numbers of digits
tmp = regexp(fileNames,'_(?<number>\d+)_(?<date>\d{4}_\d{2}_\d{2})','names');
nameStruct = cat(1,tmp{:}); %# regexp returns a cell array. Catenate for ease of use

%# maybe you want to loop, or maybe not (it's not quite clear from the question), but 
%# here's how you'd do with a loop. Anyway, since the information about the filenames
%# is conveniently stored in nameStruct, you can access it any way you want.
for iFile =1:nFiles
   %# do some processing, get the matrix M

   %# and create the output file name
   outputFileX = sprintf('newfileX_%s_%s.xls',nameStruct(iFile).number,nameStruct(iFile).date);
   %# and save
   xlswrite(outputFileX,M)
end

See regular expressions for more details on how to use them. Also, you may be interested in
uipickfiles to replace uigetfile.