Compare two cell in Matlab.

Hello, I have a question that,

if A=[ 'ddd', 'aaa']; B=['ddd']; I want to return an array that compare whether A's cell is equivalent to B's content. (sorry I know it is not well written)

So it should be [1,0] where first cell is equivalent but second is not.

However, my code has a problem:

    for j=1:Num
        temp(j)=(A{j}==B{1});
    end

that it returns a comparison of vector, for example temp(1)=[1 1 1]; How can I do a comparison and just return 1 or 0, not an array.

How can I do it vectorization?

Thanks.

Answer 1

[Star Strider]

To cast your array as cells, use curly brackets ‘{}’ rather than square brackets ‘[]’.

With that change:

A={'ddd', 'aaa'}; 
B={'ddd'};

temp = strcmpi(A,B)

produces:

temp =

       1     0

as desired.

[C Zeng]

Thanks, however, it seems not able to do a vector check, like strcmpi(A,B) that A is a vector of contents where B is just a cell.

[Star Strider]

That is because MATLAB interprets two strings in a matrix or vector as a concatenation.

So ['ddd', 'aaa'] will be intrepreted as ['dddaaa']. Using cells instead of matrices works the way you intend in your code.

[C Zeng]

I see, I read from Excel file, so it is a long column with each cell as the entry.

I will use for loop then. Thanks.

[Star Strider]

My pleasure.

A cell array as provided by xlsread should work. That would likely be the the second output provided by xlsread. (The first output would be a numeric array.)

[C Zeng]

yes, [num,txt,raw]=xlsread(filename)

So I should use the second one? However, I see txt only read non-numeric value, but I want both. P.S. in my excel file, it has both numeric and non-numeric values. so I guess I need raw?

[Star Strider]

It depends on what you are doing. To compare strings in a cell array, use the ‘txt’ output. If you are interested in accessing the numeric output in ‘num’ corresponding to a particular ‘txt’ entry, you can add that as a second assignment in your for loop.

For example:

A = {'ddd'; 'aaa'};
B = {'ddd'};

num = [1 2; 3 4];

Num = size(A,1);
for j=1:Num
    temp{j} = strcmpi(A{j},B{1});
    if temp{j} ~= 0
        data{j} = num(j,:);
    end
end
temp{:}         % Display Results
data{:}         % Display Results

[C Zeng]

Thanks Star!

[Star Strider]

My pleasure!