How to calculate mean of a cell which contains numbers and empty string?

I am working on cell in which there are 'NaN' values, along with the numbers. I need to calculate mean of 3x3 blocks after converting 'NaN' to empty string (''). I am doing this as I need mean of numbers only excluding 'NaN' entries, and '' are not counted while calculating mean. The error comes as 'mean()' can't be directly applied to cell, and I am unable to change the cell to matrix ('cell2mat'), as cell does not have all numbers but mix values.

See below for an example:

myCell ={ 1 2 3 4 5 NaN; 10 12 3 4 NaN NaN; NaN NaN NaN 1 4 5}

after replacing NaN by ''

myCell= { 1 2 3 4 5 ''; 10 12 3 4 '' ''; '' '' '' 1 4 5}

first 3x3 block is :

fisrtBlock = {1 2 3; 10 12 3; '' '' ''}

if I apply 'mean' after converting cell to matrix :

mean(cell2mat(firstBlock)),

the error is:

Error using cell2mat (line 46) All contents of the input cell array must be of the same data type.

if I try 'mean' directly: mean(firstBlock),

the error is:

Undefined function 'sum' for input arguments of type 'cell'.

Error in mean (line 28) y = sum(x)/size(x,dim);

if I try using 'cellfun':

 f = cellfun(@mean, firstBlock),

the result is:

*f =

     1     2     3
    10    12     3
   NaN   NaN   NaN*

I will appreciate any assistance for this problem. I am using MATLAB R2012a.

Answer 1

[Azzi Abdelmalek]

 To use cell2mat(A), all element of A should be the same class

[shakil]

@ Azzi, That for the reply.

I know that cell2mat() works if there are same class entries in cell, that's why I want to know if there is any other way to combine different type of elements (string , numbers) while calculating the mean.

[Azzi Abdelmalek]

What is the mean of a string?