for loop to convert cells of column to string

i have a data which is a column of cells (some string and some douple), i search for some words in it

i use this code

 for E=1:R            % from 1 : length of columns
   B=~cellfun('isempty',regexp(alldata(:,52),'BATTERY'))    % search for battrey and return 1 or 0
if (B(E) == 1)               % if value of array greater than or equal 1
    Defs(j)=E;              % save its postion (E,1)
        j=j+1;
else                     % save all arrays didn't have 'battery' separately
        not(k)=E;
        k=k+1;
end
end

but i get an error

All cells must be strings.

in line B=~cellfun('isempty',regexp(alldata(:,52),'BATTERY'))

how i can run a for loop to convert all cells into double?

i use this

 data= ' Nan ' 
data={};
data{ not( cellfun( @ischar, data ) ) } = '';

but i cant run a for loop... :(

[Amr Hashem]

sometimes when i search for a word in a column

with the same code, i got this error Index exceeds matrix dimensions.

 B=~cellfun('isempty',regexp(alldata(:,54),'BATTERY'))

it seems that some cells in the column is empty

how i can solve this

Answer 1

[Amr Hashem]

I found this answer:

 [R,C]=size(data);
H=data;
for k = 1:R
  if isnan(H{k})
    H{k} = '';
  end
end

it was answered by Jan Simon

and it works...

thanks for you all... thanks for Jan.