Comparing two tables and replacing categorical column, row wise.

Hello ,

I have two tables named Xfeat and Xfeat1, each table is having two coloumns 'feat_mat' and 'Label' . In label column there are 2 values 'Normal' and 'Hypopnea'

I need to compare Label coloumn from both the tables

Here's the code:

Xfeat.Label = categorical(Xfeat.Label);
Xfeat1.Label = categorical(Xfeat1.Label);
[a,a1]=size(Xfeat);
[b,b1]=size(Xfeat1);
c=min(a,b);
for i=1:c
    Xfeat2 = table;
    if Xfeat(Xfeat.Label(i) == 'Normal')&&Xfeat1(Xfeat1.Label(i) == 'Normal')
        Xfeat2(i,:) = [Xfeat2 ; cell2table({'Normal'})];
    else Xfeat2(i,:) = [Xfeat2 ; cell2table({'Hypopnea'})];
    end
end

This code is giving me this error:

(line 8)

Subscripting into a table using one subscript (as in t(i)) is not supported. Specify a row subscript

and a variable subscript, as in t(rows,vars). To select variables, use t(:,i) or for one variable

t.(i). To select rows, use t(i,:).

Here is a screenshot that might help

Answer 1

[VBBV]

Hi @Giridhar sai pavan kumar Konduru,

Here's one way to compare Label columns from two tables.

Do you also want to add the corresponding data from two tables to the final table ?

feat_mat =  rand(10,6);
Label1 = ["Hypopnea";"Normal";"Normal";"Hypopnea";"Hypopnea";"Normal";"Normal";"Normal";"Normal";"Normal"];
Label2 = ["Normal";"Hypopnea";"Hypopnea";"Hypopnea";"Hypopnea";"Normal";"Normal";"Normal";"Hypopnea";"Hypopnea"];
Xfeat = table(feat_mat,Label1)

Xfeat = 10×2 table
     feat_mat       Label1  
    __________    __________

    1×6 double    "Hypopnea"
    1×6 double    "Normal"  
    1×6 double    "Normal"  
    1×6 double    "Hypopnea"
    1×6 double    "Hypopnea"
    1×6 double    "Normal"  
    1×6 double    "Normal"  
    1×6 double    "Normal"  
    1×6 double    "Normal"  
    1×6 double    "Normal"  

feat_mat1 = rand(10,6);

Xfeat1 = table(feat_mat1,Label2)

Xfeat1 = 10×2 table
    feat_mat1       Label2  
    __________    __________

    1×6 double    "Normal"  
    1×6 double    "Hypopnea"
    1×6 double    "Hypopnea"
    1×6 double    "Hypopnea"
    1×6 double    "Hypopnea"
    1×6 double    "Normal"  
    1×6 double    "Normal"  
    1×6 double    "Normal"  
    1×6 double    "Hypopnea"
    1×6 double    "Hypopnea"

Xfeat.Label1 = categorical(Xfeat.Label1);
Xfeat1.Label2 = categorical(Xfeat1.Label2);
[a,a1]=size(Xfeat);
[b,b1]=size(Xfeat1);
c=min(a,b);

for i=1:c    
    if Xfeat.Label1(i) == "Normal" & Xfeat1.Label2(i) == "Normal"
        Xfeat2(i,:) = cell2table({"Normal"});
    else 
        Xfeat2(i,:) = cell2table({"Hypopnea"});
    end
end

Xfeat2

Xfeat2 = 10×1 table
       Var1   
    __________

    "Hypopnea"
    "Hypopnea"
    "Hypopnea"
    "Hypopnea"
    "Hypopnea"
    "Normal"  
    "Normal"  
    "Normal"  
    "Hypopnea"
    "Hypopnea"

Answer 2

[Stephen23]

Why are you using a loop for this? MATLAB works best when you work in terms of vectors, matrices, and arrays:

T1 = array2table(rand(10,6));
T2 = array2table(rand(10,6));
T1.Label = categorical({'Hypopnea';'Normal';'Normal';'Hypopnea';'Hypopnea';'Normal';'Normal';'Normal';'Normal';'Normal'})

T1 = 10×7 table
      Var1        Var2        Var3        Var4        Var5        Var6       Label  
    ________    ________    _________    _______    ________    ________    ________

    0.089289     0.12105      0.44055    0.78619      0.5783     0.49238    Hypopnea
     0.14026     0.98213      0.18146    0.59072    0.079402     0.64926    Normal  
     0.91114     0.70968      0.83825    0.78321     0.25092     0.43633    Normal  
     0.58606     0.30577      0.17281    0.30828     0.94065    0.021542    Hypopnea
     0.12884     0.30738    0.0020186    0.01869     0.38514     0.45546    Hypopnea
      0.8363      0.5931      0.49401    0.68917     0.19066     0.35942    Normal  
     0.53065    0.038068       0.9396    0.68979     0.54371     0.79645    Normal  
     0.41558     0.81803      0.13095    0.80943     0.62396     0.48268    Normal  
     0.32772      0.2482      0.53737    0.82553     0.68154     0.95853    Normal  
     0.68063     0.53372      0.28868    0.82927     0.13091     0.45976    Normal  

T2.Label = categorical({'Normal';'Hypopnea';'Hypopnea';'Hypopnea';'Hypopnea';'Normal';'Normal';'Normal';'Hypopnea';'Hypopnea'})

T2 = 10×7 table
     Var1        Var2        Var3        Var4        Var5        Var6        Label  
    _______    ________    ________    ________    ________    _________    ________

    0.83201     0.62591    0.072087       0.226     0.87616      0.38997    Normal  
    0.84074     0.11763     0.35808     0.82154     0.14292    0.0058556    Hypopnea
    0.36574     0.30521     0.82171      0.7092     0.75534      0.53333    Hypopnea
    0.55502     0.90404     0.31014     0.68507     0.45954       0.6906    Hypopnea
    0.35472    0.081465     0.40127      0.2254    0.059621      0.80679    Hypopnea
    0.23728     0.64749     0.68033     0.78142      0.6713      0.10198    Normal  
    0.92698     0.14575     0.77331     0.59567     0.12626      0.67265    Normal  
    0.80706     0.26028     0.39637    0.081793     0.32774      0.36823    Normal  
    0.69254     0.97409     0.81645     0.12883     0.56663      0.47115    Hypopnea
    0.61742     0.64129     0.77355     0.33023     0.72177      0.94938    Hypopnea

C = {'Hypopnea';'Normal'};
N = min(height(T1),height(T2));
X = T1{1:N,'Label'}=="Normal" & T2{1:N,'Label'}=="Normal";
D = C(1+X)

D = 10×1 cell array
    {'Hypopnea'}
    {'Hypopnea'}
    {'Hypopnea'}
    {'Hypopnea'}
    {'Hypopnea'}
    {'Normal'  }
    {'Normal'  }
    {'Normal'  }
    {'Hypopnea'}
    {'Hypopnea'}