How can I write a script to calculate conditional probability from a user created 2 way table

I have a script that gets user input and creates a table. An example looks like this:

          Yes   No     Total
Positive  15  42  57
Negative  32  9  41
Total     47  51  98

I want to then write a script that asks the user if they want to calculate conditional probability, and if they do, to prompt them to put in the row and column names they want to calculate the probability for

For example, P(Yes|Positive)

The user states the row and column names, so I'm finding it difficult to prompt for them in order to calculate the probability.

My script now is:

row = input('Enter number of rows: ');
col = input('Enter number of columns: ');
A = zeros(row + 1,col + 1);
 rowNames = input('Enter names of rows separated by a space: ', 's');
 rowNames = strsplit(rowNames); 
 colNames = input('Enter names of column separated by a space: ','s');
 colNames = strsplit(colNames);
 for i = 1:row
    for j = 1:col
      str = ['Enter element in row ' num2str(i) ', col ' num2str(j) ': '];
      A(i,j) = input(str);
    end
 end
A;
A(end,1:col) = sum(A(1:row,1:col),1);
A(1:row,end) = sum(A(1:row,1:col),2);
A(end,end) = sum(A(end,1:col));
 T = array2table(A,'VariableNames',[colNames {'Total'}],'RowNames',[rowNames, {'Total'}]);

Answer 1

[KL]

Maybe something like this?

r = input(['Please enter the choice of row for conditional probabilty (between 1 to ' num2str(numel(rowNames)) ' )']);
c = input(['Please enter the choice of column for conditional probabilty (between 1 to ' num2str(numel(colNames)) ' )']);

if(r>=1 && r<=numel(rowNames) && c>=1 && c<=numel(colNames))
    %do your thing
    %access table like, T{r,c} or T{r,end} T{end,c}
else
    disp('Chosen row/column does not exist');
end