textscan difficulties

Hello. How can i use textscan to read in a certain table that is under a user defined heading.

#  Data150
    A  B  C  D  E  
  A  1  21  7  6  4    
  B  26  2545  8  7  1
  C  10  12  2453  12  2  
  D  19  24  27  3046  6  
  E  0  0  0  0  0

My text file has a few headerlines at the top but is then listed in the above format sequentially, so theres another table underneath that has a heading # Data149. so how could I search for the heading e.g. ~ Data150 and just pick up the numbers in the table (they are seperated by tabs.

thanks

[Jason]

Just to add, I have say 150 of these tables, each on eunder its heading and descending, so at the end of the text file is Data1.

I eventually want to average all data tables say from table 1 - 50.

[Jan]

what have you tried so far to solve your problem?

I assume TEXTSCAN is not sufficient. I'd use FOPEN/FGETL/FSCANF and a WHILE loop instead.

Answer 1

[Jan]

Assuming that the data index in "# Data%d" starts at 1:

function Data = readTheData(FileName)
FID = fopen(FileName, 'r');
if FID == -1, error('Cannot open file %s.', FileName);
CC = textscan(FID, '%s', 'Delimiter', '\n');
% perhaps this in addition: 'WhiteSpace', ''
fclose(FID);

C     = CC{1};
index = find(strncmp(C, '#', 1));
Len   = numel(index);
Data  = zeros(5, 5, Len);
for i = 1:Len  
  iLine = index(i) + 1;  % Skip the header line
  for j = 1:5            % Read 5 lines
    aData = sscanf(C{iLine + 1}, ' *c %d %d %d %d %d');
    Data(j, :, i) = transpose(aData); 
  end
end

[Jason]

Hi, many thamks. Mt data index actually counts backwards so it will start say feom "# Data150" and at the end of the page have the last table with "# Data1#". I also notice when I use textscan to read in, when it reads in the numbers from the table, it just puts them all together in a single line with no spacing or tabs between them. Is it possible to tell textscan to do this -

i couldn't find it in the help.

Thankyou very much.

Jason

[Jan]

@Jason: Then you can either reorder Data afterwards: "Data = Data(:, :, end:-1:1)". Or you can consider this during the creation: "Data(j, :, Len+1-i) = ...".

Please show the inputs of TEXTSCAN. It matters if you are readibng a line using the '%s' or '%g' formats. Did you set the WhiteSpace property correctly?

Answer 2

[Jason]

Yes, I have finally got your solution to work - brilliant.

Now I have a set of matrixes called "Data". Is it possible to perform a vector sum, i.e. create another matrix where each element has been summed.

Thanks

[Jan]

Yes. See SUM(Data, Dim).