MATLAB: Convert cell array into vector

Question

I have a cell array as follows (from an operation on imported data). I want to know the locations of the numerical data i.e. where the 17 is in the list below – i'm not interested in the []s!

V =

Columns 1 through 13
    []    []    []    []    []    [17]    []    []    []    []    []    []    []
etc...

I keep on getting errors such as

Error using cell/ismember>cellismemberR2012a (line 193) Input A of class cell and input B of class char must be cell arrays of strings, unless one is a string.

when trying to use functions such as find or ismember and I think the issue is that it is a cell array and not a vector?

Thanks

Answer 1

a={[]    []    [17]    []    []}
idx=find(~cellfun(@isempty,a))