finding some specific numbers in a numeric cell array

I have a cell array that its cells contain numeric arrays of different sizes. each numeric array contains various number of numbers ranging from 7 to 13. i want to find the number and location of occurrences of all the 7s,8s,9s ...and 13s in the whole cell array. i used the following function:

I = cellfun(@(x) find(x==7), new_data, 'UniformOutput', false);

for finding 7 for example. new_data is my array. i encounter this error after running it:

Undefined function or method 'eq'for input arguments of type 'cell'.
can any body help me in this regard?

[Adam]

Are you sure you don't have nested cell arrays rather than numeric arrays inside your outer cell array?

[Andrei Bobrov]

Please show small example of your array cells.

Answer 1

[dpb]

Looks like you've nested the cell array; either create an array of cells with the double arrays each per cell or dereference inside your anonymous function--example:

>> dat(1)={randi([7 13],10,1)};   % make sample cell array 
>> dat(2,1)={randi([7 13],8,1)};  % two cells w/ a double array in each
>> whos dat
Name      Size            Bytes  Class    Attributes
dat       2x1               264  cell               
>> dat
dat = 
  [10x1 double]
  [ 8x1 double]
>> cellfun(@(x) find(x==7), dat, 'UniformOutput', false)
ans = 
  [3x1 double]
  [         5]
>> ans{:}
ans =
   7
   9
  10
ans =
   5
>> data={dat}  % now nest that in a single cell...
data = 
  {2x1 cell}
>> cellfun(@(x) find(x==7), data, 'UniformOutput', false)
Undefined function 'eq' for input arguments of type 'cell'.
Error in @(x)find(x==7)
>>

Look familiar??? :)

>> cellfun(@(x) find(x==7), data{:}, 'UniformOutput', false)
ans = 
  [3x1 double]
  [         5]
>> whos data
Name      Size            Bytes  Class    Attributes
data      1x1               324  cell               
>>

NB: The curlies "{:}" to dereference the content of the cell in the latter...

[zahra zol]

hie. thanks for answering but i hardly understand. my cell array has 332 rows 6 columns. for example, row 9th of my array is like this: [9;10;12] [9;10;12] [10;12] [7;9;10;11;12;13] [9;10;12;13] [9;10;12] others row are more or less like this one. containing numbers between 7 to 13. all i want is to determine,how many of each of these numbers exist in the whole array. and in which locations(row and column of the occurrence of each number)

[dpb]

And why doesn't the solution shown provide precisely that?

If you're still having trouble, we need to see the details of what

whos new_data

shows so we can tell what the actual structure looks like altho it would seem as I demonstrated it's the latter of a cell array within a cell given the illustration of how the specific error you received can be generated. That's not the only way, certainly, but it's about the easiest to have created (perhaps inadvertently); showing how you created the data in the first place could lead to folks here being able to show simplifications in that as well.

[zahra zol]

this is the mat file of my "new_data". forget about the last three columns. I am talking about the first six ones.

[Adam]

Your command works fine for me on your data if you remove the last 3 columns, though obviously not if you just try to run it on the whole matrix.

i.e.

cellfun(@(x) find(x==7), new_data(:,1:6), 'UniformOutput', false)

[zahra zol]

it is really odd! i had written that line of code exactly like what u just said(columns 1 to 6 specified) before. and i swear it would get back that error! and i ran it again right now and it was ok! magic! maybe it is the power of your words! thanks any way. really thanks :))

[zahra zol]

sorry but there seems to be another problem. for example when i am looking for number 13, the result matrix in row 15 has 6, 5s! that is odd because in my original matrix, row 5 has got 6 double arrays each of which contain one 13. isnt that supposed to get me 6 ones in row 15 as the result of cellfun?? and the same problem occures in other rows as well. am i doing sth wrong ?

[Adam]

find returns the index of the found item so 13 is at index 5 in each of those arrays.

If you just want to know that the value exists and not where it is then use:

cellfun(@(x) ~isempty( find(x==13) ), new_data(:,1:6));

You also don't need the UniformOutput as false in that case as the output will be a logical array.

[zahra zol]

yea that is exactly how is should be. thank you very much for your help.