MATLAB: How to filter data from table using multiple strings

filterstringstable

I have a table(60000 by 20) in which one of the columns have the following codes(extracted data):

c={'EGGD';'CSED';'CSED';'CSED';'CSED';'AVVT';'LBEB';'EGGD';'LBEB'}

And I just want the data that correspond to 'CSED' and 'AVVT'(example), there are many more.

One of my solutions:

cell=table2cell(table)
rowsCSED=any(strcmp(cell,'CSED'),2);
rowsAVVT=any(strcmp(cell,'AVVT'),2);
rows=rowsCSED | rowsAVVT;
table(rows,:)

Is there any way to do this without reverting to a loop?

Best Answer

>> t=table(categorical(c),'variablenames',{'Code'});  % put your data back into the table from whence it came
>> summary(t)
Variables:
  Code: 9x1 categorical
      Values:
          AVVT    1     
          CSED    4     
          EGGD    2     
          LBEB    2     
>> t(ismember(t.Code,{'CSED','AVVT'}),:)  % look up the matching rows...
ans = 
  Code
  ____
  CSED
  CSED
  CSED
  CSED
  AVVT
>>

NB: Such things work much better if you make the codings categorical variables rather than leaving as string data.

Related Solutions

MATLAB: How to pre-allocate table rows

Danial, I interpret your question as

"I have a table with one row. I'd need the same table, but lengthened to 10 rows so that I can fill in rows 2-9 without growing it one row at a time."

This actually isn't specific to table, although the fact that tables can hold heterogeneous types makes it a bit more interesting.

(By the way, good on you for knowing to start with {'a'}, and not just 'a'.)

One option is to simply repmat the one-row table to be 10 rows:

>> t = table({'a'},1)
t = 
    Var1    Var2
    ____    ____
    'a'     1   
>> t = repmat(t,10,1)
t = 
    Var1    Var2
    ____    ____
    'a'     1   
    'a'     1   
    'a'     1   
    'a'     1   
    'a'     1   
    'a'     1   
    'a'     1   
    'a'     1   
    'a'     1   
    'a'     1

If you're filling in the table, it doesn't much matter what's in rows 2-9, since you'll be overwriting them. But if you're a stickler, you can assign to the 11'th row, then delete it:

>> t = table({'a'},1);
>> t(11,:) = t(1,:);
>> t(11,:) = []
t = 
    Var1    Var2
    ____    ____
    'a'     1   
    []      0   
    []      0   
    []      0   
    []      0   
    []      0   
    []      0   
    []      0   
    []      0   
    []      0

Hope this helps.

MATLAB: Join multiple tables using Outerjoin in MATLAB

Outerjoin can be nested in a for loop .Please follow the example code :

T_bigtable = T{1};
for k = 2:300
  T_bigtable = outerjoin(T_bigtable, T{k});
end

Best Answer

Related Solutions

MATLAB: How to pre-allocate table rows

MATLAB: Join multiple tables using Outerjoin in MATLAB

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