Working with Excel sheets in MATLAB - excel

Question

I need to import some Excel files in MATLAB and work on them. My problem is that each Excel file has 15 sheets and I don't know how to "number" each sheet so that I can make a loop or something similar (because I need to find the average on a certain column on each sheet).
I have already tried importing the data and building a loop but MATLAB registers the sheets as chars.

Answer 1

Use xlsinfo to get the sheet names, then use xlsread in a loop.
[status,sheets,xlFormat] = xlsfinfo(filename);
for sheetindex=1:numel(sheets)
[num,txt,raw]=xlsread(filename,sheets{sheetindex});
data{sheetindex}=num; %keep for example the numeric data to process it later outside the loop.
end

Answer 2

I 've just remembered that i posted this question almost 2 years ago, and since I figured it out, I thought that posting the answer could prove useful to someone in the future.
So to recap; I needed to import a single column from 4 excel files, with each file containing 15 worksheets. The columns were of variable lengths. I figured out two ways to do this. The first one is by using the xlsread function with the following syntax.
for count_p = 1:2
a = sprintf('control_group_%d.xls',count_p);
[status,sheets,xlFormat] = xlsfinfo(a);
for sheetindex=1:numel(sheets)
[num,txt,raw]=xlsread(a,sheets{sheetindex},'','basic');
data{sheetindex}=num;
FifthCol{count_p,sheetindex} = (data{sheetindex}(:,5));
end
end
for count_p = 3:4
a = sprintf('exercise_group_%d.xls',(count_p-2));
[status,sheets,xlFormat] = xlsfinfo(a);
for sheetindex=1:numel(sheets)
[num,txt,raw]=xlsread(a,sheets{sheetindex},'','basic');
data{sheetindex}=num;
FifthCol{count_p,sheetindex} = (data{sheetindex}(:,5));
end
end
The files where obviously named control_group_1, control_group_2 etc. I used the 'basic' input in xlsread, because I only needed the raw data from the files, and it proved to be much faster than using the full functionality of the function.
The second way to import the data, and the one that i ended up using, is building your own activeX server and running a single excelapplication on it. Xlsread "opens" and "closes" an activeX server each time it's called so it's rather time consuming (using the 'basic' input does not though). The code i used is the following.
Folder=cd(pwd); %getting the working directory
d = dir('*.xls'); %finding the xls files
N_File=numel(d); % Number of files
hexcel = actxserver ('Excel.Application'); %starting the activeX server
%and running an Excel
%Application on it
hexcel.DisplayAlerts = true;
for index = 1:N_File %Looping through the workbooks(xls files)
Wrkbk = hexcel.Workbooks.Open(fullfile(pwd, d(index).name)); %VBA
%functions
WorkName = Wrkbk.Name; %getting the workbook name %&commands
display(WorkName)
Sheets=Wrkbk.Sheets; %sheets handle
ShCo(index)=Wrkbk.Sheets.Count; %counting them for use in the next loop
for j = 1:ShCo(index) %looping through each sheet
itemm = hexcel.Sheets.Item(sprintf('sheet%d',j)); %VBA commands
itemm.Activate;
robj = itemm.Columns.End(4); %getting the column i needed
numrows = robj.row; %counting to the end of the column
dat_range = ['E1:E' num2str(numrows)]; %data range
rngObj = hexcel.Range(dat_range);
xldat{index, j} = cell2mat(rngObj.Value); %getting the data in a cell
end;
end
%invoke(hexcel);
Quit(hexcel);
delete(hexcel);