Append values in a new column

Question

Ioannis Doumanis 2021-12-7

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1604710-append-values-in-a-new-column

评论： Cris LaPierre 2021-12-20

Hello all

The code below overwrites the previous values in the column Delay and inserts only the last ones (20). There should be a way to append the array instead of overwriting it but I dont know how. Any help will be appreciated

   if contains(baseFileName,"A01")
      x{k} = readtable(fullFileName,opts)
      bigtable = vertcat(x{:})
     bigtable(:,'Delay') = {10}
   elseif contains(baseFileName,"A02")
      x{k} = readtable(fullFileName,opts)
      bigtable = vertcat(x{:})
       bigtable(:,'Delay') = {20}
   end

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Answer 1

Cris LaPierre 2021-12-7

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If your tables have the same variable names (order does not matter), then just use square brackets.

newTable = readtable(fullFileName,opts)
bigtable = [bigtable;newTable];

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Ioannis Doumanis 2021-12-8

I am reading a specific data sample (300 samples) from several csv files. I want the samples the one after the other. I tried bigtable.Delay(1:6000) = 10; and still does not work. The table is filled with 0s instead of 10s and 20s. Currently I get correctly only the result (30) of the last condition of sth switch statement.

Cris LaPierre 2021-12-20

Consider sharing your data files. You can attach them using the paperclip icon.

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Answer 2

Ioannis Doumanis 2021-12-8

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I also tried this. I still get 0s for the first two conditions. I am not sure why

delayvalues = [delayvalues; delay];
for k = 1 : length(theFiles)
   baseFileName = theFiles(k).name;
   fullFileName = fullfile(theFiles(k).folder, baseFileName);
% add column at the end of the table
switch true
    case (contains(baseFileName,"A01"))
       x{k} = readtable(fullFileName,opts)
        bigtable = vertcat(x{:})
        delay = 10;
        bigtable(1:6000,'Delay') = delayvalues(1);
      case  (contains(baseFileName,"A02"))
        x{k} = readtable(fullFileName,opts)
        bigtable = vertcat(x{:})
          delay = 20;
        bigtable(6000:12000,'Delay') = delayvalues(2);
    case (contains(baseFileName,"A03"))
        x{k} = readtable(fullFileName,opts)
        bigtable = vertcat(x{:})
          delay = 30;
        bigtable(12000:18000,'Delay') = delayvalues(3);
    
    otherwise
           % do nothing
end 