MATLAB: How to separate table columns by groups

tableunstack

If I have a table of data (T1) such as:

Var1 Var2
1     xyz
1     xyy 
2     xxx
2     xzx
3     xyy
4     yzy
4     xzz
4     yzz

I would like to output another table (T2):

Var1      Var2
1        xyz,xyy
2        xxx,xzx
3          xyy
4      yzy,xzz,yzz

I have unsuccessfully used unstack, since it creates the values in Var2 as column names. Any suggestions would be much appreciated.

Best Answer

If Var2 is a categorical array, then I assume that your xyz,xyy is actually a 1x2 categorical array [xyz, xyy], not a char array. If so:

T1 = table([1;1;2;2;3;4;4;4], categorical({'xyz';'xyy';'xxx';'xzx';'xyy';'yzy';'xzz';'yzz'}))
varfun(@(values) {values'}, T1, 'GroupingVariables', 'Var1')

Related Solutions

MATLAB: How to create a matrix, table or a cell where in odd columns variables from matrix A and in even columns variabls from matrix B will be stored

This should work for numeric, cell and table, although Adam's is likely more efficient for numeric:

>> x1 = array2table(rand(3))
x1 =
  3×3 table
     Var1        Var2       Var3  
    _______    ________    _______
    0.77917     0.56882    0.33712
    0.93401     0.46939    0.16218
    0.12991    0.011902    0.79428
>> x2 = array2table(randn(3),'VariableNames',{'Var4' 'Var5' 'Var6'})
x2 =
  3×3 table
      Var4        Var5        Var6  
    ________    ________    ________
    -0.88803     0.30352     0.73936
     0.10009    -0.60033      1.7119
    -0.54453     0.48997    -0.19412
>> x = [x1 x2]
x =
  3×6 table
     Var1        Var2       Var3        Var4        Var5        Var6  
    _______    ________    _______    ________    ________    ________
    0.77917     0.56882    0.33712    -0.88803     0.30352     0.73936
    0.93401     0.46939    0.16218     0.10009    -0.60033      1.7119
    0.12991    0.011902    0.79428    -0.54453     0.48997    -0.19412
>> x = x(:,[(1:3)+[0;3]]) % requires 16b or later, otherwise use bsxfun
x =
  3×6 table
     Var1        Var4        Var2        Var5       Var3        Var6  
    _______    ________    ________    ________    _______    ________
    0.77917    -0.88803     0.56882     0.30352    0.33712     0.73936
    0.93401     0.10009     0.46939    -0.60033    0.16218      1.7119
    0.12991    -0.54453    0.011902     0.48997    0.79428    -0.19412

MATLAB: Remove rows of a table based on values in an array

disp('Original table');
var1=[1;1;1;1;4;1];
var2=[2;2;2;2;5;2];
var3=[0;3;3;8;8;9];
table_data=table(var1,var2,var3)
n=histc(var3(:),var3);
disp('Updated table');
table_data(find(n==1),:)=[]

Result Window:

Original table
table_data =
  6×3 table
    var1    var2    var3
    __    ____    ____
    1       2       0   
    1       2       3   
    1       2       3   
    1       2       8   
    4       5       8   
    1       2       9   
    
Updated table
table_data =
  4×3 table
    var1    var2    var3
    ____    ____    ____
    1       2       3   
    1       2       3   
    1       2       8   
    4       5       8

Best Answer

Related Solutions

MATLAB: How to create a matrix, table or a cell where in odd columns variables from matrix A and in even columns variabls from matrix B will be stored

MATLAB: Remove rows of a table based on values in an array

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