Create cell array of column indices of a specific string

Hi,

I have a 5x1 cell array ,g, where each cell is 40x50. I want to find the column indices of the string 'Latitude' in each of the cells in the cell array. I know there is 7 occurences of this string in each of the cells but I want the code to tell me that. My desired output is a new cell array where each cell contains the column indices of this string (so it will end up being a 5x1 cell array where each cell contains the 7 column indices). I tried this:

ind=find(~cellfun('Latitudes', g));

but it won't work. Any suggestions would be much appreciated

Thank you

Answer 1

[Voss]

% make cell array g
g = repmat({repmat({''},40,50)},5,1);
% put 7 random 'Latitude's in each cell
for ii = 1:5
    g{ii}(randi(2000,7,1)) = {'Latitude'};
end

% get the column index of each instance of 'Latitude'
cidx = cellfun(@get_latitude_columns,g,'UniformOutput',false)

cidx = 5×1 cell array
    {7×1 double}
    {7×1 double}
    {7×1 double}
    {7×1 double}
    {7×1 double}

% put them together in a matrix, if you prefer
% (5x7 or 7x5, whatever makes sense to you)
cidx = [cidx{:}].'

cidx = 5×7

2 3 19 20 30 48 50 8 8 10 11 25 36 46 10 28 29 29 31 32 42 14 16 17 22 34 43 45 2 19 21 25 36 39 50

function idx = get_latitude_columns(s)
[~,idx] = find(strcmp(s,'Latitude'));
end

[Davindra Usov]

Hi,

thank you so much for your reply. Did you mean to write 'g' instead of 's' in the function? & did you have to write your function in a separate script?

[Voss]

Hi, You're welcome!

I meant 's'. I could've called it any valid variable name, as long as it's the same name used on the next line - that's what matters.

I didn't have to use a function, but it was convenient to do so.

[Davindra Usov]

Ah, I see! was your function intended to be written at the end of your script? (sorry, MATLAB newb here :') )

[Voss]

Yes, at the end of the script.

The function could also have been in its own m-file, called "get_latitude_columns.m".

[Davindra Usov]

Thank you so much, it worked!!

[Voss]

You're welcome!