Add '_max' to odd variable names and '_min' to even ones.

I have a table where just even variables have a name, the rest (odd) have automatic name set by Matlab.

Something like this:

I want to have Var1 = t_max and t = t_min, then Var3 = ang_azi_max and ang_azi = ang_azi_min.

Hope someone can help ;)

Answer 1

[Stephen23]

T = array2table(rand(5,8),'VariableNames',{'Var1','t','Var3','ang_azi','Var5','vel_azi','Var7','acc_azi'})

T = 5×8 table
     Var1         t         Var3       ang_azi     Var5      vel_azi     Var7      acc_azi
    _______    _______    _________    _______    _______    _______    _______    _______

    0.64569    0.92867    0.0076932    0.65038    0.92731    0.53037    0.45407    0.55135
    0.94421    0.22754      0.50774    0.82564    0.97646    0.69373    0.55652    0.26508
    0.83117    0.69494      0.93597    0.35117    0.89839     0.7037     0.9437    0.52426
     0.8657    0.26734     0.017575    0.80891    0.79093    0.22237    0.93816    0.57082
    0.79332    0.75431      0.40472    0.97708    0.26331    0.52194    0.94611    0.63532

T.Properties.VariableNames(1:2:end) = strcat(T.Properties.VariableNames(2:2:end),'_max');
T.Properties.VariableNames(2:2:end) = strcat(T.Properties.VariableNames(2:2:end),'_min')

T = 5×8 table
     t_max      t_min     ang_azi_max    ang_azi_min    vel_azi_max    vel_azi_min    acc_azi_max    acc_azi_min
    _______    _______    ___________    ___________    ___________    ___________    ___________    ___________

    0.64569    0.92867     0.0076932       0.65038        0.92731        0.53037        0.45407        0.55135  
    0.94421    0.22754       0.50774       0.82564        0.97646        0.69373        0.55652        0.26508  
    0.83117    0.69494       0.93597       0.35117        0.89839         0.7037         0.9437        0.52426  
     0.8657    0.26734      0.017575       0.80891        0.79093        0.22237        0.93816        0.57082  
    0.79332    0.75431       0.40472       0.97708        0.26331        0.52194        0.94611        0.63532  

[Usune Elizondo]

Thank you very much is working perfectly!

Answer 2

[Simon Chan]

Suppose the table is called T, then try the following:

T.Properties.VariableNames(1:4) = {'t_max','t_min','ang_azi_max','ang_azi_min'}

[Usune Elizondo]

The problem is that it is a large table with more than 1500 variables, I would like to do this through the whole table, with a for loop or somthing similar, any ideas?

[Simon Chan]

Try this:

temp = T.Properties.VariableNames(2:2:end);
temp_min = cellfun(@(x) strcat(x,'_min'),temp,'UniformOutput',false);
temp_max = cellfun(@(x) strcat(x,'_max'),temp,'UniformOutput',false);
temp_combine = vertcat(temp_max, temp_min);
T.Properties.VariableNames = temp_combine(:);

[Stephen23]

@Simon Chan: STRCAT also operates on cell arrays of char vectors, so CELLFUN is entirely superfluous.