Importing periodic data with textscan and fgetl?

Question

William 2012-11-21

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/54427-importing-periodic-data-with-textscan-and-fgetl

回答： Y. J. 2018-5-7

Here's a subset of the data I'm trying to import into MATLAB:

Time =  0.50734E-01
     X             Y             Z             EP_g    
  23.865        25.227      -0.50000       0.56828      
  24.135        25.227      -0.50000       0.56839      
  23.865        25.500      -0.50000       0.56834      
  24.135        25.500      -0.50000       0.56831      
Time =  1.00059E-01
     X             Y             Z             EP_g    
  23.865        25.227      -0.50000       0.56828      
  24.135        25.227      -0.50000       0.56840      
  23.865        25.500      -0.50000       0.56835      
  24.135        25.500      -0.50000       0.56832

I am trying to import this data using textscan and fgetl but have been having trouble. The problem is those pesky lines between each subset.

The column on the far right (EP_g) is the only thing I'm really interested in. By the time I'm done, I just want a matrix with the transpose of the EP_g column along the rows, i.e.,

   data =
      0.56828 0.56839 0.56834 0.56831
      0.56828 0.56840 0.56835 0.56832

My attempt at a solution:

   fid=fopen(file)
   while ~feof(fid)
       tmp=textscan(fid,'%f%f%f%f','Headerlines',5)
       for j=[1:2]
           fgetl(fid)
        end;
   end; 
   fclose(fid);

I would appreciate any guidance or help you can give me. Many thanks!

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Answer 1

William 2012-11-21

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/54427-importing-periodic-data-with-textscan-and-fgetl#answer_66127

在 MATLAB Online 中打开

I managed to get it to work by using only the textscan function. I had seen an example using fgetl and I thought I needed it for this application, but it turns out I didn't.

 fid=fopen('n90deg');  % Open file
 c=1;                  % Initialize counter
 while ~feof(fid);     % Run until end of file
    tmp=textscan(fid,'%f%f%f%f','Headerlines',2);  % Omit first two lines every 
                                                   % time
    n90deg(c,:)=tmp{4}';  % Store the last cell as a row in new matrix
    c=c+1;                % Add to counter and repeat above steps
 end
 fclose(fid);

Hopefully someone else will find this useful.

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Answer 2

Azzi Abdelmalek 2012-11-21

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/54427-importing-periodic-data-with-textscan-and-fgetl#answer_66125

在 MATLAB Online 中打开

fid = fopen('file.txt');
line1 = fgetl(fid);
res=line1;
while ischar(line1)
line1 = fgetl(fid);
res =char(res,line1)
end
fclose(fid);

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Azzi Abdelmalek 2012-11-21

编辑：Azzi Abdelmalek 2012-11-21

在 MATLAB Online 中打开

fid = fopen('data3.txt');
line1 = fgetl(fid);
res=line1;
while ischar(line1)
line1 = fgetl(fid);
res =char(res,line1)
end
fclose(fid);
n=size(res,1)-1
ii=0;
for k=1:6:n
  ii=ii+1
data{ii}=str2num(res(k+2:k+5,:))
t=regexp(res(k,:),'=','split')
t1{ii}=str2num(t{2})
end

William 2012-11-21

Yes, that makes much more sense. I was trying str2mat and str2cell but didn't try str2num. Thank you very much Azzi!

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Answer 3

Y. J. 2018-5-7

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链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/54427-importing-periodic-data-with-textscan-and-fgetl#answer_318998

在 MATLAB Online 中打开

Hey guys i have a simmilar problem. My File looks like this:

       06.12.2099 13:50:37
  502C43 ZU152323
  Radial
f  acceleration
b  kg
  Example value
1/3  t = 0 s
+0.0000e+00  +1.4013e-03
+1.4648e+02  +2.6760e-05
+2.9297e+00  +2.1846e-06
+4.3945e+04  +1.5014e-10
+5.8594e+00  +7.3407e-40
+7.3242e+06  +6.7897e-06
2/3  t = 0.682667 s
+0.0000e+00  +1.4013e-03
+1.4648e+02  +2.6760e-05
+2.9297e+00  +2.1846e-06
+4.3945e+04  +1.5014e-10
+5.8594e+00  +7.3407e-40
+7.3242e+06  +6.7897e-06
3/3  t = 0.682667 s
+0.0000e+00  +1.4013e-03
+1.4648e+02  +2.6760e-05
+2.9297e+00  +2.1846e-06
+4.3945e+04  +1.5014e-10
+5.8594e+00  +7.3407e-40
+7.3242e+06  +6.7897e-06

And i read the two value columns like this:

 fmt = '%f %f';
fid=fopen('Example.txt,'r');
k = 1;
while (~feof(fid))
    k = k+1;
    c(k-1,1) = textscan(fid,fmt,'collectoutput',true,'HeaderLines',7);
end
fid=fclose(fid);

This works fine and he stores me the Values for each time separately. But I need also the time value after "t = ". And it should be saved in my cell also. at the moment i get a 3x1 cell (in this case).

Thank you in advance.