Indexing several Data files to extract a column from each file

Hello,

I have 10000 different *.xls files. I have imported them to my workspace and would like to extract only column 3 from each of the 10000 files. Each file has 10 columns.

Having extracted the 3rd column from each file, I would like to preallocate a matrix where the 10000 columns would be stored as my output file.

Assume that my file has length(15000) as it contains daily precipitation timeseries for a long period.

I appreciate your response.

Zilefac.

[ASONG ZILEFAC]

Additionally, the 10000 files have a common extension .xls and different names. However, the names are numerical and increase sequentially by a factor of 1 e.g 001.xls, 002.xls etc.

[Matt J]

Clarify what "length(15000)" means. Is it the number of rows in the desired output?

[ASONG ZILEFAC]

Hello Matt,

length(15000) is the number of rows in the input file.

Answer 1

[Azzi Abdelmalek]

A=zeros(15000,1000);
for k=1:1000
filename=sprintf('file%d.xls',k)
  num=xlsread(filename)
  A(:,k)=num(:,2)
end

Answer 2

[Sachin Ganjare]

With xlsread command you can read partcular column in xls file.

Below link will be useful in this regard:

http://www.mathworks.in/help/matlab/ref/xlsread.html

Hope it helps!!!