MATLAB: How to get and write data from text file

command linedatalooptext file

Text file as follows:
  • A column: Year (1998:1:2017)
  • B column: Day of the year (1:1:365 or 366)
  • C column: Hour
1998 152 1 30 25 12.5
1998 152 1 30 30 12
1998 152 1 30 35 11.8
1998 152 1 30 40 11.9
1998 152 1 30 45 12
I would like to get data but I have problem for leap year of 366 days. I'd like to extract all rows and then write data to text file, which is D= 30 and E=25 and B>=152 and B<=243 but it changes B>=153 and B<=244 according to leap years. I tried something but I got 0 and 1. How can I write text file what I want?
load fulltable.txt;
yearlenght = 365+(eomday(fulltable(:,1),2) == 29);
if fulltable(:,1) == yearlenght; 
test = fulltable(fulltable(:,2)>=153 & fulltable(:,2)<=244 & fulltable(:,4)==30 & fulltable(:,5)==25,:);
else fulltable(:,1) ~= yearlenght; 
test = fulltable(fulltable(:,2)>=152 & fulltable(:,2)<=243 & fulltable(:,4)==30 & fulltable(:,5)==25,:);
end

Best Answer

This code sorts the file data into one cell array C, where each cell in C contains the summer data for one year. The summer start and end dates are adjusted for the leap years.
mat = dlmread('fulltable.txt');
ily = (mod(mat(:,1),4)==0&mod(mat(:,1),100))|~mod(mat(:,1),400); % leap year.
idx = mat(:,2)>=(152+ily) & mat(:,2)<=(243+ily); % summer start and end dates.
idr = find(idx);
idg = cumsum([true;diff(idr)~=1]); % years into group numbers.
idz = find(mat(:,4)==30 & mat(:,5)==25); % match D and E column data.
fun = @(r){mat(intersect(r,idz),:)};
C = accumarray(idg,idr,[],fun);
And checking the start and end dates by looking at the first and last few rows of some of the cells:
>> C{1}(1:4,:)
ans =
         1998          152            1           30           25         12.5
         1998          152            3           30           25         10.9
         1998          152            5           30           25          9.6
         1998          152            7           30           25          8.4
>> C{1}(end-3:end,:)
ans =
         1998          243           17           30           25         34.6
         1998          243           19           30           25         32.5
         1998          243           21           30           25         29.4
         1998          243           23           30           25         20.5
>> C{3}(1:4,:)
ans =
         2000          153            1           30           25         29.6
         2000          153            3           30           25         25.4
         2000          153            5           30           25         20.8
         2000          153            7           30           25         15.7
>> C{3}(end-3:end,:)
ans =
         2000          244           17           30           25         44.3
         2000          244           19           30           25         44.8
         2000          244           21           30           25         37.4
         2000          244           23           30           25         29.5
You can then simply loop over the cells of the that cell array and export the data in files. Read the documentation to know how to access data in a cell array and save sequential files:
https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-cell-array.html
https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html
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