Convert some Table Variables from Cell to Double

Hello everybody,

I have a table with many variables of mixed types (some strings, some numbers).

and I would like to convert some of them as double/numeric type. Based on HoldNames.

I hope to make the HoldNames' columns to double in the table. Please some helps.

I tried with for loop. But I think there might be more matlab-like way (fancy) to do it.

% Create table of cells
var = num2cell(rand(4,3));
Names = {'Steve';'John';'Paul';'Evan'};
var = [var,Names];
T = splitvars(table(var));

% Below code to verify the Data Type
varfun(@class,T,'OutputFormat','cell')   %  {'cell'}    {'cell'}    {'cell'}    {'cell'}

% Convert Var_2 and Var_3 to double 
HoldNames={'var_2','var_3'};


% Below Code is working. But I think there might be more matlab-like way to do it.
for i = 1:length(HoldNames)
    val(i) = find(strcmpi(T.Properties.VariableNames,HoldNames(i)));
end
for i = 1:length(HoldNames)
    if iscell(T.(val(i)))
        T.(val(i)) = str2double(T.(val(i)));
    end
end
% Below code to verify the Data Type. Now converted Var_2 and Var_3 to double 
varfun(@class,T,'OutputFormat','cell')   % {'cell'}    {'double'}    {'double'}    {'cell'}

Answer 1

[Walter Roberson]

for i = 1 : length(holdNames)
    thisname = holdNames{i};
    T.(thisname) = str2double(T.(thisname));
end

[Smithy]

Thank you very much. It works really well.

Answer 2

[Lei Hou]

The funciton 'convertvars' is designed to be a convenient way to type conversion of table variable. Regarding your use case, you can do

>> T = convertvars(T,{'var_2','var_3'},'cell2mat')

T =

  4×4 table

      var_1        var_2      var_3       var_4  
    __________    _______    _______    _________

    {[0.4088]}    0.48851    0.19976    {'Steve'}
    {[0.1418]}    0.46403    0.31925    {'John' }
    {[0.5649]}     0.9611    0.62927    {'Paul' }
    {[0.2521]}    0.12603    0.12671    {'Evan' }