How to convert cell to numeric

I have used "readtable" in order to import the same column from several excel. The type of data is "1P", "2P"...."6P". Once MATLAB has imported them, I use table2array to convert the table into an array. After this operation, I'd like to convert the values of each cell into numeric, I mean, convert the cell with 1P into 1, 2P into 2... 6P into 6. I have tried it by using "cell2mat" and then "str2num" but it doesn't work. Anyone can help me?

Thanks in advance.

for i=1:12
    energia_activa(:,i)=readmatrix(meses(i),'Range','C2:C2999');
    energia_reactiva(:,i)=readmatrix(meses(i),'Range','D2:D2999');
    periodo(:,i)=readtable(meses(i),'Range','F2:F2999'); 
end
potencia_consumida=energia_activa.*4;

%Periodos
periodo_numcar=table2array(periodo);
periodo_num=zeros(2997,12);

for i=1:12
    periodo_num=cell2mat(periodo_numcar(:,i));
end

[Rik]

It is not quite clear to me what your data actually is, but why do you expect cell2mat to know what you want? You should write a parsing function that will convert your input char array to a value. Then you can either use a loop or cellfun to process the entire array.

(and don't use str2num, use str2double instead)