MATLAB: How to delete ‘NA’ columns from a text file

natext file

Hi guys, I have a text file which has 7 rows and 499 columns and in some columns, there are 'NA'
How can i delete them?
 Example.txt:
NA      T2b   t1c  t3b
60      79     78      50
7        7     9         7
t2c      t3a    t2c  t3b
4        5     3      NA
0.1  0.1    0.18    0.1 
4      4      5     3

Best Answer

This is easy with textscan, strcmp, and some indexing:
opt = {'MultipleDelimsAsOne',true};
fmt = repmat('%s',1,4); % define how many columns!
[fid,msg] = fopen('test.txt','rt');
assert(fid>=3,msg)
C = textscan(fid,fmt,opt{:});
fclose(fid);
C = [C{:}];
idx = any(strcmp(C,'NA'),1);
D = C(:,~idx);
which generates this matrix:
D =
  T2b   t1c
  79    78
  7     9
  t3a   t2c
  5     3
  0.1   0.18
  4     5
The test file is attached to this answer. It is also easy to write this to a new file:
tmp = D';
len = max(cellfun('length',D(:)));
fmt = sprintf('%%-%ds',len+1);
fmt = [repmat(fmt,1,size(D,2)),'\n'];
[fid,msg] = fopen('test_new.txt','wt');
assert(fid>=3,msg)
fprintf(fid,fmt,tmp{:});
fclose(fid);
this generates a new file which looks like this:
T2b  t1c  
79   78   
7    9    
t3a  t2c  
5    3    
0.1  0.18 
4    5
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