Return the number of rows of an array of cell data

I have an array of cell data “a” in Matlab. I want to look at the array (which contains numeric and text data) and say in Matlab speak: Find what row of “a” says: ‘Temp Height (density)’.

The Code will return b=1326; I was thinking something like:

[row,col] = find(a, {‘Temp  Height  (density)’});

This will then give me the value row=1326 which is what I need. I tried to use the find function but it doesnt seem to work becasue it tells me: Undefined function or method 'find' for input arguments of type 'cell'.

Help on this is much appreciated.

Answer 1

[Sven]

If your cell contains strings (and not numeric data), just use strcmp:

[row,col] = find(strcmp('Temp  Height  (density)', a));

If some elements of your cell are numeric, the above will fail ( UPDATE: Actually, the above works fine even for non-char elements... I'll leave the rest of my answer for reference). Another method uses the cell function below:

[row,col] = find(cellfun(@(c)ischar(c)&&strcmp('Temp  Height  (density)',c),a))

or do it in two steps:

strInds = find(cellfun(@ischar, a));
matchMask = strcmp('Temp  Height  (density)'), a(strInds));
[row,col] = ind2sub(size(a), strInds(matchMask));

[charles atlas]

That strcmp function worked perfectly, Thanks.

I can't believe there was such a simple solution to this problem.

Answer 2

[Paulo Silva]

doc cellfun

Answer 3

[Walter Roberson]

Is the text to appear anywhere in the row of the cell array (i.e., text might be intermixed without any order), or is it to appear in a very specific column (e.g., column 3) of the cell array, or is it to appear in any of several known columns?

Is the text a substring of the text that is there? A leading substring? A trailing substring? Always the complete string?

If it is a very specific column, say 3, and forms the whole of the column, then

[tf, rowidx] = ismember(‘Temp  Height  (density)’, a(:,3));