Error using *equal* when indexing information for creating a structure

Hi all,

I am trying to create a structure, by indexing from a cell array (which I define as follows):

Behaviours = {"Wall Jump"; "Move Isolated"; "Rear Isolated"; "SAP";
    "Stop Isolated"; "Huddling"; "Contact"; "Move in contact"}

Here is the code for creating the structure:

for k =1:size(Behaviours)
    AnimalData(k).behaviour = Behaviours(k);
    AnimalData(k).All_Instances = dat(dat.NAME == Behaviours(k), :);
end

I wish to loop through each of these behaviours, and want to make a structure that contains all the information that I have in relation to each of these behaviours. However, when I try to pull the behavioural data from the "dat" structure that contains all my data I get the following error:

Error using  ==  (line 25)
Invalid types for comparison.

Line 25 corresponds to the last line of my "for" loop. If I replace "Behaviours(k), :) with one of my behaviours, I do not get this error.

Can someone tell me what I am doing wrong?

[Adam Danz]

What is stored in dat.NAME? Could you show us an example copied from your command window?

Here are some things to fix,

1. If you're using a string array, use square brackets: ["Wall Jump", ..., "Move in contact"];
2. When comparing strings or char-arrays, use strcmp() or strcmpi():. strcmpi(dat.NAME, Behaviours(k))

[Amy Hassett]

To give you an idea, here is my dat Table.

Making the changes you recommend, here is the new code:

for k =1:size(Behaviours)
    data(k).behaviour = Behaviours(k);
    data(k).All_Instances = dat(strcmp(dat.NAME, Behaviours(k))); 
end

When I run it, data.All_Instances is just a bunch of empty cells. Any advice?

[Adam Danz]

I continued the discussion in the answers section.

Answer 1

[Adam Danz]

It doesn't look like you applied the recommendation correctly.

strcmp() returns a logical vector identifying which rows are a match. Try this.

 data(k).All_Instances = dat(strcmp(dat.NAME, Behaviours(k)),:);

[Amy Hassett]

This gave an empty set, but it did make me think to try this:

for k =1:size(Behaviours)
    data(k).behaviour       =       Behaviours(k);
    data(k).All_Instances   =       dat(dat.NAME == data(k).behaviour, :);
end

Which worked!

[Adam Danz]

If you attach a mat file containing the dat table, I could take a look at what's happening.

save('datData.mat', 'dat')

Are you sure the variables you're working with are string arrays rather than cell arrays of character vectors?