How can i match value in file and write the match corresponding row in new file

I need to extract the matching value and corresponding row in new file

Data

Col1 Col2 Col3 Col4 Col5 Col6 Co7

222 -10.894943 127.960434 0.0136 -0.2221 0.0292 0.0192

223 -10.944739 127.979071 0.0272 -0.2237 0.0293 0.0188

222 -10.994533 127.997716 0.0163 -0.2263 0.0293 0.0185

223 -11.044324 128.016368 0.0217 -0.2273 0.0292 0.0182

224 -11.094114 128.035028 -0.0085 -0.2282 0.0290 0.0178

223 -11.143902 128.053696 0.0448 -0.2298 0.0288 0.0174

224 -11.193688 128.072371 0.0234 -0.2301 0.0287 0.0170

223 -11.243472 128.091055 0.0476 -0.2320 0.0285 0.0166

From that data i must extract the row like this

File 222

222 -10.894943 127.960434 0.0136 -0.2221 0.0292 0.0192

222 -10.994533 127.997716 0.0163 -0.2263 0.0293 0.0185

file 223

223 -10.944739 127.979071 0.0272 -0.2237 0.0293 0.0188

223 -11.044324 128.016368 0.0217 -0.2273 0.0292 0.0182

223 -11.143902 128.053696 0.0448 -0.2298 0.0288 0.0174

I am thinking to use

for i=1:data(:,1)
    idx_match=find(data(;,1)==data(;,1)) %matching value in data using Col1
    write                                  %wite in new file
end

I am confused to set reference in matching process

[Chunru]

data = [222     -10.894943  127.960434    0.0136 -0.2221  0.0292  0.0192
  223     -10.944739  127.979071    0.0272 -0.2237  0.0293  0.0188
  222     -10.994533  127.997716    0.0163 -0.2263  0.0293  0.0185
  223     -11.044324  128.016368    0.0217 -0.2273  0.0292  0.0182
  224     -11.094114  128.035028   -0.0085 -0.2282  0.0290  0.0178
  223     -11.143902  128.053696    0.0448 -0.2298  0.0288  0.0174
  224     -11.193688  128.072371    0.0234 -0.2301  0.0287  0.0170
  223     -11.243472  128.091055    0.0476 -0.2320  0.0285  0.0166];

ufiles = unique(data(:,1))

ufiles = 3×1

222 223 224

for i=1:length(ufiles)
    idx = data(:,1) == ufiles(i);
    selected_data = data(idx, :);
    % write the data to file
end

[Retno Purwaningsih]

That's work!!

Thank you for the explanation :D

Answer 1

[Wan Ji]

If, for example, your data can be read by readtable function. File name is 'Data.txt', File format is as following:

  Col1         Col2            Col3               Col4    Col5    Col6        Co7
  222     -10.894943  127.960434    0.0136 -0.2221  0.0292  0.0192
  223     -10.944739  127.979071    0.0272 -0.2237  0.0293  0.0188
  222     -10.994533  127.997716    0.0163 -0.2263  0.0293  0.0185
  223     -11.044324  128.016368    0.0217 -0.2273  0.0292  0.0182
  224     -11.094114  128.035028   -0.0085 -0.2282  0.0290  0.0178
  223     -11.143902  128.053696    0.0448 -0.2298  0.0288  0.0174
  224     -11.193688  128.072371    0.0234 -0.2301  0.0287  0.0170
  223     -11.243472  128.091055    0.0476 -0.2320  0.0285  0.0166

Then run the following script:

clc; clear
yourTable = readtable('Data.txt');
column1 = yourTable.Col1;
[column1, idx] = sort(column1);
yourTable = yourTable(idx,:);
[~, ia] = unique(column1);
fileSegment = diff([ia;numel(column1)+1]);
tableCell = mat2cell(yourTable, fileSegment, size(yourTable,2));
celldisp(tableCell) % if file too large,skip this command by using '%'
% write to new files, file name 'table*.txt'
arrayfun(@(i) writetable(tableCell{i},['table',num2str(i),'.txt']),...
    1:1:numel(tableCell));

celldisp output will be

tableCell{1} =
 
    Col1       Col2          Col3        Col4      Col5       Col6      Co7  
    ____    __________    __________    ______    _______    ______    ______

    222     -10.894943    127.960434    0.0136    -0.2221    0.0292    0.0192
    222     -10.994533    127.997716    0.0163    -0.2263    0.0293    0.0185

 
 
tableCell{2} =
 
    Col1       Col2          Col3        Col4      Col5       Col6      Co7  
    ____    __________    __________    ______    _______    ______    ______

    223     -10.944739    127.979071    0.0272    -0.2237    0.0293    0.0188
    223     -11.044324    128.016368    0.0217    -0.2273    0.0292    0.0182
    223     -11.143902    128.053696    0.0448    -0.2298    0.0288    0.0174
    223     -11.243472    128.091055    0.0476     -0.232    0.0285    0.0166

 
 
tableCell{3} =
 
    Col1       Col2          Col3        Col4       Col5       Col6      Co7  
    ____    __________    __________    _______    _______    ______    ______

    224     -11.094114    128.035028    -0.0085    -0.2282     0.029    0.0178
    224     -11.193688    128.072371     0.0234    -0.2301    0.0287     0.017
    

Files are generated in the work directory

Also, this way is much faster than comparing them one by one!

[Retno Purwaningsih]

I used that code and found error like this,

Undefined function 'write' for input arguments of type

'double'.

Error in writetable (line 124)

write(a,filename,varargin{:})

Error in

reformat>@(i)writetable(tableCell{i},['table',num2str(i),'.txt'])

Error in reformat (line 24)

arrayfun(@(i)

writetable(tableCell{i},['table',num2str(i),'.txt']),...

[Wan Ji]

writetable writes the table to a file, but not matrices of type double. So try to convert the matrix to a table at first. Your raw data is actually a matrix, isn't it? Please make sure to use readtable to get the data by

yourTable = readtable('Data.txt');

IF you just want to let data be a matrix, then instead

clc; clear
% data is a matrix 
yourTable = table(data); 
column1 = data(:,1);
[column1, idx] = sort(column1);
yourTable = yourTable(idx,:);
[~, ia] = unique(column1);
fileSegment = diff([ia;numel(column1)+1]);
tableCell = mat2cell(yourTable, fileSegment, size(yourTable,2));
celldisp(tableCell) % if file too large,skip this command by using '%'
% write to new files, file name 'table*.txt'
arrayfun(@(i) writetable(tableCell{i},['table',num2str(i),'.txt']),...
    1:1:numel(tableCell));

[Wan Ji]

@Retno Purwaningsih

[Wan Ji]

Or you can change merely this line

arrayfun(@(i) writetable(tableCell{i},['table',num2str(i),'.txt']),...
    1:1:numel(tableCell)); % this line works only when tableCell{i} is a table

to

arrayfun(@(i) writetable(table(tableCell{i}),['table',num2str(i),'.txt']),...
    1:1:numel(tableCell)); % this line works when tableCell{i} is a table or a matrix

[Retno Purwaningsih]

Yess !!! that's working

But, if i want the file name of new file corresponding with the unique value from column 1 how do i write the code? I want to remover header in the first row and use space as the delimiter.

I used this code but not working.

arrayfun(@(i) writetable(table(tableCell{i}),['table',unique(Column1){i},'.txt'],'Delimiter',' ','WriteVariableNames',0),...
        1:1:numel(tableCell));

[Retno Purwaningsih]

@Wan Ji

[Wan Ji]

arrayfun(@(i) writetable(table(tableCell{i}),['table',num2str(Column1(ia(i))),'.txt'],'Delimiter',' ','WriteVariableNames',0),... 1:1:numel(tableCell)); TRY this command.