# What is the difference between "any" and "all" function?

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##### 11 Comments

James Tursa
on 7 Jun 2023

x = nan(100000000,1); % full x

nnz(x)

timeit(@()nnz(x))

Note that in the full x case, there is no shortcut and you need to take the time to examine each element. In the sparse x case, the number of nonzero elements has already been calculated by MATLAB when building the sparse martix and is sitting at the end of the internal column indexing array Jc, so all you have to do is grab that element and return it. Very fast. But it relies on the definition of nonzero including NaN.

James Tursa
on 12 Jun 2023

Response from TMW:

There were 2 main concerns you had:

- Consistent treatment of NaN values for the “nnz”, “all”, and “any” functions
- Consistent treatment of NaN values between the sparse and regular matrices when using the “any” function

The second issue will be fixed in a future release to ensure consistency in the “any” function.

We will consider addressing the first issue but will first wait to see if other users have the same concern.

### Answers (5)

Image Analyst
on 21 Feb 2023

any returns true if any of the elements are non-zero, while all returns true only if all of them are non-zero. For all to return true, there must not be a single 0 in the array. If there is even a single zero, then all() will return false.

v = [1 0 3 5]

any(v)

all(v) % Not all are non-zero because the second element is not non-zero

v = [1,2,3,4]

any(v)

all(v) % Every single element is non-zero -- ALL of them.

##### 0 Comments

Torsten
on 21 Feb 2023

vec = [0 5 7];

Is any element of "vec" equal to zero ? Yes, the first one:

any(vec)

Are all elements of "vec" equal to zero ? No, only the first one:

all(vec)

##### 0 Comments

Sulaymon Eshkabilov
on 21 Feb 2023

There is one significant difference between any() and all(). Here are definitions:

(1) any() - any True if any element of a vector is a nonzero number or is

logical 1 (TRUE). any ignores entries that are NaN (Not a Number).

(2) all() - all True if all elements of a vector are nonzero.

A = [1 1 0 1 0];

any(A)

all(A)

Another example - B = [1 1 1 1 1];

B = [1 1 1 1 1];

any(B)

all(B)

Another example - C = [ 0 0 0 0 0];

C = [ 0 0 0 0 0];

any(C)

all(C)

##### 0 Comments

Walter Roberson
on 21 Feb 2023

any: at least one of the inputs is non-zero

all: every input is non-zero

Mathematically, all(x) works out the same as ~any(~x)

- 0 0 any=false all=false
- 0 1 any=true all=false
- 1 0 any=true all=false
- 1 1 any=true all=true

any(x) is sum(x(:)~=0)>0

all(x) is sum(x(:)~=0)==numel(x)

##### 0 Comments

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