Remove specific entry in a cell array

I want to remove an entry in a cell array if it is equal to something specifically. Explained in this example:

animals={'cat', 'dog', 'mouse', 'horse'};

"animals" is being redefined in a loop, and if it happens to be redefined with 'dog' as an entry, I want to remove it. So I want

animals={'cat', 'mouse', 'horse'};

I don't want to replace 'dog' with a blank (''), I want to remove that entry entirely and keep the array tight (i.e. reduce the dimensions from 4x1 to 3x1 in this case).

Thanks

Answer 1

[James Tursa]

animals(ismember(animals,'dog')) = [];

[Nischal Amin]

This does not work for me.

X = ('Cat', 'Dog', 'Tiger');

X = X(ismember(X,'Tiger')) == []

X should be 'Cat', 'Dog', Empty cell

Basically, I don't want the X index to change. I just want to remove Tiger. So, when I do unique(X)...it displays only Cat and Dog.

[Jan]

X = ('Cat', 'Dog', 'Tiger') is no valid Matlab syntax. For a cell array you need curly braces, not parentheses.

X(ismember(X,'Tiger')) == [] compares the cell {'Tiger'} with the empty matrix. It does not set anything to the empty cell.

X = {'Cat', 'Dog', 'Tiger'};
X(ismember(X,'Tiger')) = {''}

X = 1×3 cell array
    {'Cat'}    {'Dog'}    {0×0 char}

% Or faster:
X = {'Cat', 'Dog', 'Tiger'};
X(strcmp(X, 'Tiger')) = {''}

X = 1×3 cell array
    {'Cat'}    {'Dog'}    {0×0 char}

Answer 2

[Akira Agata]

Another way to do it:

idx = strcmp(animals,'dog');
animals(idx) = [];

[Jan]

If only one string has to be removed, this is the fastest solution. +1

Answer 3

[Jan]

animals = {'cat', 'dog', 'mouse', 'horse'};
animals = setdiff(animals, {'dog'})

This would allow to remove multiple elements at once.

[jaah navi]

I tried with your command in the following code:
code:
 C = partitions([5 7 8 50])
 partitions = setdiff(partitions, {'5','7'}).But i am getting error.
could you please help me to remove {'5','7'}.

[Jan]

Please post the error message instead of only mentioning, that there is one. By the way, which partitions do you mean? This is not a function of the Matlab toolboxes, so we cannot know, what you are talking of. At least it looks strange, that the input of this function is numeric, and you expect the output to be a cell string.

[Peter Jarosi]

setdiff() unexpectedly sorts cells. What if I dont want this side effect?

animals = {'cat', 'dog', 'mouse', 'horse'};
animals = setdiff(animals, {'dog'})

animals = 

    'cat'    'horse'    'mouse'

OK, I found the answer, using 'stable' option. Nice! I really appreciate your idea. Thanks!

animals = {'cat', 'dog', 'mouse', 'horse'};
animals = setdiff(animals, {'dog'}, 'stable')

animals = 

    'cat'    'mouse'    'horse'

[Jan]

@Peter: If you want to remove one string only:

animals = {'cat', 'dog', 'mouse', 'horse'};
animals = animals(~strcmp(animals, 'dog'))

[Peter Jarosi]

@Jan: Actually I applied your idea for removing more than one string from a cell array. (I just used your example to illustrate the problem of sorting.) In my opinion the most convenient method is yours extending with 'stable' option, if we want to remove more than one strings and keep the original order of the remaining elements.

[RITESH KUMAR]

can we write element number at place of dog. it is at 2nd place. can i write 2.

[Arpit Agarwal]

cool